Kagan will be the choice unless Obama can find one of those wiz kids that jsut graduated law school at the age of 19.
I think it depends on whether he wants to provoke a fight in the Senate. He has a good chance at avoiding a filibuster with Garland, which is why I think Obama will probably go with him.
Even Specter voted against Kagan for Solicitor General, on the other hand. A fight to confirm a justice as liberal as Kagan isn’t something the Democrats want before this year’s elections, and it’s a fight they’re more likely to lose after the election when the Republicans will have a largely defection-proof filibuster.