Well, possibly Kessler, if he ever gets back to fighting non-tomato cans. And if Bute defeats Andrade decisively, then he's a candidate. After that, the top three MWs are either at SMW now or soon to be: Taylor, Pavlik, Abraham. And finally, Dirrell.
It has the potential to be a very exciting division in boxing, especially when Pavlik and Abraham decide to finally move and join the Bute, Kessler, Taylor, Pascal, Froch, Miranda, Andrade, etc...