If she runs she wins. I think she will run, because she is still a rising star in the Democratic Party. If she runs, we're likely to see a flip-flop with Sebelius going to the Senate and Brownback going to Topeka. Voters will probably view that as a "fair-trade".
Sebelius will win if she runs, but I don't think she will.
Uh, guys, if she runs she'll still be a favorite to lose. Imagine if there was an open seat in Rhode Island, it doesn't mean that their governor, a popular Republican, would win.
Sebelius may run, and she may win, but she'd have a harder time running without a GOP Lt. Governor like she has in the past and a simple aura of competence in order to win the day: senate races are far more partisan affairs.
Read as: Get real and wake up in the real world. Sebelius will have at least a slightly uphill battle to climb, but it's doable