I really don't think WWE has a definitive #2 draw right now, which explains why the people they are pushing always shifts dramatically and people like Taker, Brock, Rock, and Triple H are still carrying the load at the big ppv's. Having these people work part time schedules is pretty counterproductive to establishing new draws because their rarity on television creates a certain "mystique" about them that makes fans want to see them more than anyone.
If I were judging only from what I read from fans on the internet, then CM Punk and Daniel Bryan are already bigger than Cena. But we all know that's not the case.