According to Politico Tim Kaine is very high on the short list.
As Senator Barack Obama turns to the choice of his running mate, Virginia Gov. Tim Kaine has emerged as one of the campaign’s potential finalists, sources familiar with conversations in Richmond and in Chicago said.
Kaine, an early Obama supporter whose biography nicely dovetails with the Illinois senator’s, "ranks very, very high on the short list," said a source who has spoken recently to senior Obama aides about Kaine.
Kaine "is getting a critical examination," the source said.
This doesn't surprise me. I like Tim Kaine, and think he would be a great choice for these reasons:
Kaine's position as governor of a state the Obama campaign hopes to make a key battleground and his background as a Spanish-speaking former Catholic missionary and civil rights lawyer make him a strong potential pick.
Kaine could serve as ambassador, his proponents say, to four key groups: Virginians, Catholics, working-class white voters, and Hispanics. (Kaine can be seen in one YouTube video endorsing Obama in proficient Spanish.
I think it's more important for Barack to be seen as picking a "change agent" rather than someone who "shores up weaknesses". The only problems I could see would be associated with Tim Kaine's fighting with the Virginia legislature.
Updated: Apparently he's also pro-life... Is it a deal breaker? Not for me, but only because I think that he would "become" pro-choice.