What states are in play?
Here are the states where people on the Forum assert competitiveness (the ones I think are genuinely competitive are asterisked):
Arizona - Kyl's approvals aren't great, but the Dems' candidates suck. Very outside chance of competitiveness.
Connecticut - Lieberman has a number of interesting challengers, but unless something major happens.
Florida - If Katherine Harris is the nominee, the genreal consensus is that there will be a landslide. Otherwise, this may be competitive.
Maryland* - Steele's verbal gaffes may make for an eventually uncompetitive race, but any race with Mfume will not be a Democratic landslide. Cardin may be a different story.
Michigan - Polls show the not exceptionally well-known or popular Stabenow beating her opponents by very solid margins, but not ones that I would call completely safe.
Minnesota* - So far, it appears to be tooth and nail.
Mississippi - I think there's a guy named Mike Moore who supposedly could make for a competitive race under some circumstance. I'm not entirely sure I should be including this, but I forget the details of the race.
Missouri* - A recent poll says Talent has taken back a small-medium lead, but before then McCaskill was leading regularly by small numbers in poll returns.
Montana* - New polls show Burns down.
Nebraska - Until I see polling information, I'm not sure I can entirely label this seat as safe - if I ever can.
Nevada - I don't think this is worth including at all, but if Las Vegas Mayor Oscar Goodman runs, this could theoretically be competitive.
New Jersey* - Another very competitive seat.
Ohio* - Has moved around a lot, but generally seems competitive.
Pennsylvania* - No need to explain.
Rhode Island* - Chafee either leads by unspectular margins or doesn't.
Tennessee* - I think this may drift into the GOP column, but for now polls generally show marginal Republican leads.
Washington - The Washington GOP does nothing better than produce mediocre candidates that lose by moderate margins that aren't moderate enough to call seats safe.
Very few, if any, people argue that California, Delaware, Hawaii, Indiana, Maine, Massachusetts, New Mexico, New York, North Dakota, Texas, Utah, Vermont, Virginia (as long as Warner does not run), West Virginia, Wisconsin or Wyoming will be competitive.
So I'd personally say nine states are competitive, and an additional eight are standard pie-in-the-sky fare for partisans that have a very distant chance of becoming competitive.