According to The Wrestling Observer, word from within WWE is that the company has been discussing making a major name the leader of the Nexus faction. Two names that have been pitched already are Triple H and John Cena.
As everyone knows, WWE has always been against turning Cena heel because of his merchandise sales and the amount of younger fans he always draws to WWE events.
As for Triple H, he has wanted to make another heel turn for the past few years, but the timing for this has never been right thanks to injuries and other issues.
The Wrestling Observer