The fact that WWE is pointing at a member of DX as the obvious winner is a signal, if anything, that neither of them are winning. The beauty of HBK vs Taker, if it happens, is how HBK will get that match, and I don't think they will take the cheap route of just having HBK win. That's if they do decide on having HBK vs Taker II, if not, then HBK is completely out of the picture.
HHH winning the rumble is, to me, also out of the picture. HHH would rather put himself in the underdog role and be the last man eliminated by the man who wins it, then getting on revenge mode leading into winning the Elimination Chamber. That is, if they plan on doing HHH vs Sheamus. If he's battling HBK, then dont even bother doing math on him.
Cena is the man who needs winning the rumble the most. All people have feuds to fall into if they don't win the rumble. Should HBK not win the Rumble, he can still end up with Taker or with HHH. HHH can still end up against Sheamus or HBK without the Rumble. Cena either wins the Rumble or he gets screwed of a until now visible marquee match.