You are not the Amazing Kreskin. McCaskill goes down in Mizzou as does Tester in Montana. Lieberman will ALWAYS vote with the dems. You don;t need to be the Amazing Kreskin to predict that!
If everyone else votes either Democrat or Republican, it won't matter whether Lieberman votes Democrat or abstains. If the vote for everyone else is 50R-49D, the Republicans will win regardless of what Lieberman does; if it's 49R-50D, the R's will lose unless Lieberman votes for them. Consequently, I wouldn't be too surprised if Lieberman votes for neither party.