While I'm skeptical about a lot of the VP tea-leaf reading surrounding the recently announced DNC schedule, it does strike me that the selection of Mark Warner as the keynote speaker is suggestive. While Hillary Clinton does speak the same night, it still seems to me that, in an election year so wracked with gender conflict, it would be somewhat insensitive to have the nominee, VP, and keynote speaker all be dudes. Which in turn suggests that Obama may have already picked a woman as his VP. And if he's picked a woman she's almost certainly Kathleen Sebelius.
Consider the list of previous keynote speakers. The last white guy (Evan Bayh) was in 1996, and before that the last one was in 1984 -- when we the VP nominee was Geraldine Ferraro (before that there were a lot of dudes, but that was a time when the list of female office holders was pretty limited). The keynote speech has, traditionally, been a way to balance out the ticket's demographic weaknesses. What's more, the keynote is also traditionally a way to highlight rising stars in the party but, given his abortive presidential candidacy, Warner is hardly a new face. That suggests even more strongly he's been chosen to balance the demographics of the speakers.
--Sam Boyd