Who I think it will be? Emanuel. Who I would like? Biden.
Biden's actually a really good choice. Dude's 73 but I get the sense he's still full of energy and ideas and not at all ready to retire yet. Lord knows he has the connections and experience. Jeff Bingaman would be another smart old guy choice.
What the dems really need is someone clever... another LBJ or Reagan-type figure who could outfox the Republicans. Who are the clever Dems? The only one I can think of is Harry Reid and he's obviously not going to do it. Bill Clinton and Barack Obama also fit that category but won't take such a demotion.
Honestly I'm down with all the Dean love on this thread. Just go ask Howard Dean who he'd like it to be and beg him to spend a year teaching that person everything he knows.