Seems to me the joker in the deck is Silky Pony. Whoever he throws his delegates to will probably get a majority on the first ballot.
Say Obama wins Ohio, Pa and TExas by the same margin he won Wisconsin. The additional 57 delegate votes that the Edwards has will still not be enough togive Obama the nomination on the first ballot.
We know Obama went to see Edwards. We can be pretty sure he asked for Obama's delegates. In fact it is likely that Obama presented his internal polls on the remaining states. He wanted to prove he was a shoe in and get Edwards 57 delegates. But we know Obama did not get them. What we know is Obama could not or would not meet the Silk Pony's price.
So I think Edwards wants to wait until either Obama or Hillary get within 57 delegates of the nomination and then trade his votes for the VP nomination.