Additionally with the 58th seat now almost a lock in Alsaska he will add two R senators to his cabinet to flip those seats.
Specter for HHS? Snowe for Homeland Security?
Maybe some enticements for Collins, Voinovich, Grassley, Roberts, Bond, Alexander, Corker, Gregg, Brownback, McConnell, Bunning, or Burr?
Those are the only potential opportunities for flipping seats, because those would be all the R Senators (ordered by voteview.com lib-con ranking, except that Specter is more conservative than Collins) in states with D governors who would then be able to appoint D Senators.
IMO Specter is the one most likely to get picked off, because he's really old and frail and will have the fight of his life in 2010 against Gov. Rendell, who is really popular in the state and he's fairly liberal for a Republican anyway.