Your overall race ratings for Senatorial Races

[Mr. Smith]

I'm switching Michigan into Safe D, and South Dakota into Tilt R with Rounds falling apart. The rest remains the same

[Del Tachi]

AK: Toss-Up / Advantage R
AL: Safe R
AR: Lean R
CO: Tossup / Advantage D
DE: Safe D
GA: Likely R
HI: Safe D
IA: Tossup / Advantage R
ID: Safe R
IL: Safe
KS: Tossup / Advantage Orman
KY: Likely R
LA: Tossup / Advantage R
MA: Safe D
ME: Safe R
MI: Likely D
MN: Safe D
MS: Safe R
MT: Safe R
NC: Leaning D
NE: Safe R
NH: Likely D
NJ: Safe D
NM: Safe D
OK: Safe R
OK-Special: Safe R
OR: Safe D
RI: Safe D
SC: Safe R
SC-Special: Safe R
SD: Safe R
TN: Safe R
TX: Safe R
VA: Likely D
WV: Likely R
WY: Safe R

[The Other Castro]

AK: Tossup/Tilt R
AL: Safe R
AR: Tilt/Lean R
CO: Tossup/Tilt D
DE: Safe D
GA: Tilt/Lean R
HI: Safe D
IA: Tossup/Tilt R
ID: Safe R
IL: Safe D
KS: Tilt/Lean I
KY: Tilt/Lean R
LA: Tilt R
MA: Safe D
ME: Safe R
MI: Likely D
MN: Safe D
MS: Safe R
MT: Safe R
NC: Lean D
NE: Safe R
NH: Likely D
NJ: Safe D
NM: Safe D
OK: Safe R
OK-Special: Safe R
OR: Safe D
RI: Safe D
SC: Safe R
SC-Special: Safe R
SD: Lean R (honestly no idea wtf is going on here)
TN: Safe R
TX: Safe R
VA: Safe D
WV: Safe R
WY: Safe R

[morgieb]

Safe D

Delaware
Hawaii
Illinois
Massachusetts
Michigan
Minnesota
New Jersey
New Mexico
Oregon
Rhode Island
Virginia

Likely D

New Hampshire

Tilt D

Kansas (well...Tilt I)
North Carolina

Toss-up

Colorado

Tilt R

Alaska
Georgia
Iowa
Louisiana

Lean R

Arkansas
Kentucky
South Dakota

Safe R

Alabama
Idaho
Maine
Mississippi
Montana
Oklahoma (both of them)
South Carolina (ditto)
Tennessee
Texas
West Virgina
Wyoming

[dmmidmi]

Safe D

Delaware
Hawaii
Illinois
Massachusetts
Michigan
Minnesota
New Jersey
New Mexico
Oregon
Rhode Island
Virginia

Likely D

New Hampshire
North Carolina

Tilt D

None

Toss-up

Alaska
Arkansas
Colorado
Iowa
Kansas
Louisiana

Tilt R

Georgia

Lean R

Kentucky
South Dakota

Safe R

Alabama
Idaho
Maine
Mississippi
Montana
Oklahoma (x2)
South Carolina (x2)
Tennessee
Texas
West Virgina
Wyoming

[MATTROSE94]

Safe D
Rhode Island
Delaware
New Mexico
Illinois
Massachusetts
New Jersey
Hawaii
Virginia
Oregon

Likely D
Michigan
Minnesota
New Hampshire

Lean D
None

Pure Toss-Up
Louisiana
Alaska
Arkansas
Iowa
North Carolina
Colorado
Kansas

Lean R
Kentucky
Georgia (Due to runoff election)

Likely R
South Dakota

Safe R
West Virginia
Montana
Tennessee
Nebraska
Maine
Texas
Mississippi
South Carolina (R)
South Carolina (S)
Oklahoma (R)
Oklahoma (S)
Idaho
Wyoming
Alabama

[nolesfan2011]

Senate:

Safe D: HI, NM, OR, NJ, DE, RI, MA, VA
Likely D: IL
Leans D: NH, NC, MN, MI

Safe R: ID, WY, MT, NE, OK(x2), SC(x2), AL, TN, TX
Likely R: ME, WV, MS
Leans R: KY

Pure Toss-Up: IA, AR, CO

Tilt D/I: KS
Tilt R: AK, SD

Goes to runoff: GA, LA (advantage GOP in both)

so the Senate makeup would be 49-47 GOP (+1 Indie Orman) before toss-ups, and if I predict out toss-ups I have it 51-49 advantage GOP, assuming Orman caucuses with Dems.

[ElectionsGuy]

I think this is worth bumping one last time.

Safe D:

Everything else

Lean D:

New Hampshire
North Carolina

Toss-Up/Tilt I:

Kansas

Toss-Up:

Georgia
Iowa

Toss-Up/Tilt R:

Colorado

Lean R:

Alaska
Arkansas
Louisiana

Likely R:

Arkansas
Kentucky
South Dakota

Safe R:

Montana
West Virginia
Everything else

[tmthforu94]

Safe D
Rhode Island
Delaware
New Mexico
Illinois
Massachusetts
Minnesota
New Jersey
Hawaii
Oregon

Lean D
Michigan
New Hampshire
Virginia

Toss-Up
Georgia
Iowa
North Carolina
Kansas

Lean R
Alaska
Arkansas
Colorado
Kentucky
Louisiana
South Dakota

Safe R
West Virginia
Montana
Tennessee
Nebraska
Maine
Texas
Mississippi
South Carolina (R)
South Carolina (S)
Oklahoma (R)
Oklahoma (S)
Idaho
Wyoming
Alabama

[nolesfan2011]

Senate:

Safe D: HI, NM, OR, NJ, DE, RI, MA, VA
Likely D: IL
Leans D: NH, NC, MN, MI

Safe R: ID, WY, MT, NE, OK(x2), SC(x2), AL, TN, TX
Likely R: ME, WV, MS
Leans R: KY

Pure Toss-Up: IA, AR, CO

Tilt D/I: KS
Tilt R: AK, SD

Goes to runoff: GA, LA (advantage GOP in both)

so the Senate makeup would be 49-47 GOP (+1 Indie Orman) before toss-ups, and if I predict out toss-ups I have it 51-49 advantage GOP, assuming Orman caucuses with Dems.

Less than 2 weeks away update.

Safe D: HI, NM, OR, NJ, DE, RI, MA, VA
Likely D: IL, MN
Leans D: MI

Safe R: ID, WY, MT, NE, OK(x2), SC(x2), AL, TN, TX
Likely R: ME, WV, MS
Leans R: KY

Pure Toss-Up: IA, CO
Tilt D/I: KS, NH
Tilt R: AK, SD, AR

Goes to runoff: GA, LA (advantage GOP in both)

GOP would theoretically be at 50 (after the LA, and GA runoffs) without needing to win CO or IA... but in order to get Senate control they need to take everything they lean in (GA, LA, AR, SD, AK and KY) plus 1 of CO or IA. Iowa would seem to be a little easier to do.

If Dems lose KS or NH it's over

Projecting out, I have IA going to the GOP and Colorado staying Dem.. so projected senate makeup 51-49 GOP once it is all set and done

[NewYorkExpress]

10 Days away, this is how I see things

Alabama- The question is what the primary will look like if Shelby retires in 2016. Safe R

Alaska- While Senator Begich is behind, he's far from done yet. One of several states where the National Climate will mean everything. Tossup/Tilt R

Arkansas- While the result may be close, the outcome is not in doubt, Tom Cotton will win this one. Safe R

Colorado- Despite Senator Udall's meltdown, I still think Governor Hickenlooper is more likely to lose. Lean D

Delaware- With no Christine O'Donnell, election night will very boring here Safe D

Georgia- Senator Nunn has won a marvelous campaign, and it's starting to look like she may win a runoff after all. Tossup Tilt/D

Illinois- Senator Durbin's margin will be reduced, but he will still win easily. Safe D

Idaho Safe R

Iowa- This is a race that will be decided by who gaffed least, and where the National mood is going. That probably favors Joni Ernst. Tossup/Tilt R

Kansas The most unpredictable race this far, will Republican Moderates who abandoned Roberts come home? I think they will, and that will put him just over the top.
Tossup/Tilt R

Kentucky- While Alison Grimes has done well, she didn't so enough. An upset is still plausible, but increasingly unlikely Likely R

Louisiana Mary Landrieu is likely toast, but that frees her up for a challenge against Senator Vitter in the 2015 Gubernatorial Race. Likely R/Cassidy

Maine Susan Collins may cross 75% of the vote, which is amazing for a relative moderate in today's day and age. Safe R

Massachussets- Safe D

Michigan Terri Lyn Land has ultimately proven to be the Republican Alison Grimes. Likely D

Minnesota Thankfully, this race will not resemble 2008 at all. Safe D

Mississippi Travis Cochran's primary victory appears to have locked this one up. Safe R

Montana This one's long gone. Safe R

Nebraska Safe R

New Hampshire Scott Brown certainly can win this race, but Senator Shaheen remains the favorite. Lean D

New Jersey Senator Booker is in even less danger than last year. Safe D

New Mexico The other Senator Udall is much safer. Safe D

North Carolina Senator Hagan's in trouble, but she's facing a more unpopular candidate. Advantage Hagan. Tossup/Tilt D

Oklahoma- Both races are Safe R

Oregon No reason for Jeff Merkley to worry.  Safe D

Rhode Island Safe D

South Carolina Both seats are Safe R

South Dakota- Even with Governor Rounds's struggles, this fractured field can only help him. Lean R

Tennessee- Safe R

Texas Safe R

Virginia Senator Warner should survive, but an upset is not impossible. Likely D

West Virginia Natalie Tennant has been a bust, and State Democrats should look forward to being the long-term minority here. Safe R

Wyoming Safe R

[morgieb]

Safe D

Delaware
Hawaii
Illinois
Massachusetts
Michigan
Minnesota
New Jersey
New Mexico
Oregon
Rhode Island
Virginia

Lean D

New Hampshire

Tilt D

North Carolina

Tilt R

Alaska
Colorado
Georgia
Iowa
Kansas
Louisiana

Lean R

Kentucky
South Dakota

Likely R

Arkansas

Safe R

Alabama
Idaho
Maine
Mississippi
Montana
Oklahoma (both of them)
South Carolina (ditto)
Tennessee
Texas
West Virgina
Wyoming

[Pessimistic Antineutrino]

Safe D
Delaware
Hawaii (special)
Illinois
Massachusetts
Minnesota
New Jersey
New Mexico
Oregon
Rhode Island
Virginia

Likely D
Michigan

Lean D
New Hampshire
North Carolina

Tossup/Tilt D
None

Tossup/Tilt I
Kansas

Pure Tossup
Alaska

Tossup/Tilt R
Arkansas
Colorado
Georgia
Iowa
Louisiana

Lean R
Kentucky
South Dakota

Likely R
West Virginia

Safe R
Alabama
Idaho
Maine
Mississippi
Montana
Nebraska
Oklahoma
Oklahoma (special)
South Carolina
South Carolina (special)
Tennessee
Texas
Wyoming

[Amenhotep Bakari-Sellers]

Tossup

AK, IA, CO, La and GA, KY

LD 

NH, KS, MI

LR 

AR, Mnt, WVa, SD

[SPC]

Just to test the idea that 538 actually confers any additional knowledge besides that of a typical polling average, I computed a polling average for all the races based on polling data since September 15, calculated the standard error of the mean for each set of data multiplied by 3 (a number determined empirically by calculating the error for the 2010 and 2012 races.) Here is what I gathered:

Republican chance of victory:
Georgia 85%¹
Alaska 84%
South Dakota 75-80%²
Iowa 69%
Louisiana 67%²
Arkansas 65%
Kentucky 57%
Colorado 53%
New Hampshire 26%
Kansas 21%
North Carolina 13%

¹85% chance of plurality on Election Day. Assuming Swafford gets ~3%, there's a 55% chance of a runoff.
²95% for Rounds vs Weiland; 80% for Rounds vs Pressler
³There's a 73% chance of a runoff, in which Cassidy would have a 91% chance

The main areas of disagreement seem to be in the Republican-held battlegrounds, where sparse polling data forces greater reliance on fundamentals, it would seem.

Updates:

Colorado 87% (+32)
South Dakota 92% (+12)
Arkansas 83% (+18)
Kentucky 78% (+21)
Iowa 74% (+5)
Louisiana 63% (-4)¹
Kansas 50% (+29)
Georgia 48% (-37)
North Carolina 29% (+16)
New Hampshire 15% (-11)

*Nonpartisan polling has been too sparse in Alaska to make a projection. Thus, I will assume that Sullivan's probability remains 84%

¹ 70% of runoff, in which Cassidy would have a 90% chance

[Maxwell]

Putting Colorado as the most likely pick-up is pretty bold, I don't agree at all, but I do think Gardner's chances are very good.