Richardson, Bayh, and Biden are out. They've been slotted into speaking slots at the DNCC, and none of them are for that Wednesday night keynote the veep nominee will get.
Most people seem to be going with Kaine. But I'm going to stick with Trapper John's call:
Tom Daschle
(Personally still hoping its Sebelius.)
Update: As many point out in the comments, convention speaker schedules can be moved around, so perhaps we can't read anything into the current roster. Perhaps. We're all flying blind here, so it's all just idle speculation. And I see nothing wrong with that.