The VP pick will be Biden.
HRC would likely galvanize as many presently dispirited Republicans as she would disaffected women. (who still, in the final tally are not likely to go Repub)
Sebilius would tick off the HRC supporters.
Kaine reinforces Obama's perceived negatives -- youth, lack of foreign policy bona fides.
Bayh ....not a great campaigner, supported the Iraq invasion. and would probably not bring Indiana.
Biden, while he can be undisciplined on the stump is a beast of a campaigner and will get after McCain day in and day out on the campaign trail, something Obama has not shown a taste for doing to this point. Additionally, Biden has Pennsylvania roots -Scranton-. HRC played her Pa. "roots" in the primary to good effect. It would likely do no less for Biden.
For all Obama's desire to run a 50-state race, you must first win, before you dominate. This race will turn on Ohio, Michigan and Pennsylvania and their 20, 18, 21 electoral votes.