Although Fox News is not calling the Indiana primary, in exit polls Clinton leads by 7% among Democrats, a bit less among Republicans crossing over. She polls behind Obama 49% to 51% among Independents. [Overall, Clinton leads 52% to 48% in the exit polls.]
If the polls are accurate, it sounds like a 3-10% win in Indiana for Clinton, perhaps more if there is a Bradley Effect.
With 5% of the Indiana votes counted, Clinton leads 59% to 41%.
UPDATE: At about 8:10pm ET, CBS called Indiana for Clinton.
2d UPDATE, 11:30pm ET: I recently returned from the Becker-Posner rational choice workshop at Chicago. So far only CBS has called it for Clinton. And Lake County near Chicago seems to be holding back its votes. It could go either way.
3d UPDATE, 12am ET: Things are beginning to look like they are trending toward Obama in Indiana, but it's too soon to tell.