One of the best blogs, in my opinion, for following the primaries has been Al Giordano's The Field. He has actually himself traveled to many primary states and done some fantastic on the ground reporting, as well as some interesting analysis and primary predictions.
Today, his latest post is titled "The Nightmare Ticket is Dead". In it, he makes the claim that multiple sources have confirmed to him that Hillary Clinton has directly, personally, asked Barack Obama to make her his running mate, and that Obama has politely but firmly declined.
According to an update, the Clinton campaign has denied Al Giordano's reporting in their most recent conference call, as posted at TalkLeft.
I personally find this to be entirely believable and possible, and like Al Giordano I think it would go a long way towards explaining Hillary's increasingly bizzare and ludicrous remarks about seating the Michigan and Florida delegations.