I was at a speech given by David Wilhelm (Bill's campaign manager in 1992 that came out to support Obama) and when asked this question the only person he mentioned as someone he'd like to see Obama choose is Jim Webb.
Webb would presumably shore up the national security/military issue, but almost as important is that he would play very well to the lower income white males.
Lastly, the only candidate that keeps bringing up the idea of a joint ticket is the one that realizes it would be their only way to win.
He's been in the Senate even less time than Obama, right? I doubt that he would be an option.
Jim Webb will never do it. I don't think "politicking" is his thing.
He's not an option becuase he brings years and years of experience in the Senate. It's because he is a genuine war hero, was appointed to several positions involving the military during the Reagan administration, and called the Iraqi invasion one of the worst strategic blunders in modern history back in 2003.
The problem with Jim Webb in the #2 spot is that he would be about as biddable as Bill Clinton. I like the guy a lot, but he's not one to subordinate his opinions for the greater good.
The guy was in the military. Subordination is the foundation of that experience. Also, he's still a politician. No one goes to Washington D.C., without thinking about whether he/she can eventually get to 1600 Pennsylvania.