I would have bet money (if I had any, that is) that we would have known who Obama chose for his running mate by now, 16:00 on Friday.
I'm going to predict that he chooses Hillary Clinton. I think she would be the wise choice and having the Clinton machine behind Obama would, in my opinion, make them pretty unbeatable.
We'll see if I'm right, won't we? (Of course, I haven't been right about any of the candidates, so I'd recommend not holding your breath!)