Amy Walter of National Journal writes it up:
4. Missouri: Given Obama's victories in North Carolina and Indiana, the fact that John McCain won Missouri (albeit narrowly) shows just how tough it will be for Democrats to take the outgoing Christopher (Kit) Bond's seat. Democrats are lining up behind Secretary of State Robin Carnahan, while Republicans may have a nasty primary between Rep. Roy Blunt and former state Treasurer Sarah Steelman. The Steelman camp has released a poll showing Carnahan beating Blunt, who will carry the baggage of 13 years in D.C., including a stint in leadership. Carnahan, meanwhile, will be running for the first time as a national Democrat, not just a Missouri Democrat. This will be a very close race.
Kentucky Sen. Jim Bunning is listed as the most vulnerable GOP incumbent; Connecticut Sen. Chris Dodd is seen as the weakest DEM officeholder