Al Giordano of The Field is reporting that an Obama-Clinton ticket is a non-starter:
The Field can now confirm, based on multiple sources, something that both campaigns publicly deny: that Senator Clinton has directly told Senator Obama that she wants to be his vice presidential nominee, and that Senator Obama politely but straightforwardly and irrevocably said “no.” Obama is going to pick his own running mate based on his own criteria and vetting process.
h/t Andrew Sullivan.