Obama's choice for the Veep slot is unlikely to be Senator Clinton.
The corpse of the Clinton campaign continues to make its way through the remaining primaries but she remains in the race for several possible reasons; a possible huge stumble by Obama accompanied by a mass departure of the super delegates, a last ditch chance the campaign can convince the DNC to seat Florida and Michigan according to their disputed primaries, her need to satisfy the delusional supporters still showing up at her rallies in hopes of her pulling off a Harry Truman turn around or possibly she truly believes Obama is not electable.
It is unlikely she remains just for the Veep slot, she has already proven she is a potential candidate for the slot. Yet, Obama will not choose Clinton, he does not need to be overshadowed by her at any time; possibly drawing larger crowds than him or potentially in the White House. She does not bring anything to the table as far as geography or ideology that he does not already possess. Clinton does not shore up any of Obama's shortcomings.
He will pull her voters without her on the ticket, once they have a cooling period, they are true Democrats and their fingers will recoil before they vote for a Republican. She may not have pulled his voters because she made race such a big issue, but he will get her voters in the end.
What Clinton would bring to the ticket that Obama does not want is her polarizing personality where she has as high of unfavorables as just about anyone (except W) and along with Bill, who seems to be a drag on her campaign, are seen as old time slash and burn political operators something Obama has rigorously campaigned against.
Obama's greatest weakness heading into the fall against McCain is foreign policy and absent the economy going completely in the tank, the focus of the election will continue to be that and the war. McCain masterfully shifted the focus and debate back to his strength by announcing 2013 as a date we will be out of Iraq and Bush reinserted himself by taking a swipe at Obama, all in an attempt to frame the issues. The choice of VP will likely be made prior to any more economic disasters, therefore Obama's choice will be heavily favored to foreign policy and shoring up an exit strategy beyond words.
Sam Nunn for VP, a well respected former Senator with foreign policy and defense experience as chair of the Armed Services committee. Nunn is from the south, having represented Georgia and he is thought to be a conservative Democrat. He shores up Obama's weaknesses in just about every aspect; he adds age, experience and stability to the ticket, ideology and geography and hits the gap with foreign policy.
Obama/Nunn vs. McCain/?