Actually, my active hatred for Crocodile was kind of doused by the Baroque Works cover arc. Crocodile is chained up and at the mercy of the World Government, then his old employees show up to save him (when he probably doesn't even deserve to be saved!) and he just calmly lights a cigar and says, "Nope, don't feel like being rescued." And then his secret wish is revealed: he wants (still, deep-down) to be Pirate King and he just glares down at the revelation with outrage as if to say, "I thought I outgrew this!" But no, he hasn't. And then when he learns that he's going to be shipped off to Impel Down, he smiles! I may not like him, even now after he saved Ace, but I can't help but respect what a wonderful complex villain he is. Oda is awesome in making a Piccolo-like character where his redemption (not so much the become-one-of-Luffy's-nakama redemption, but a redemption nonetheless) is actually believable given the circumstances. I honestly think that after the events at Marineford are played out, he will become a real pirate once again and become one of Luffy's grudgingly respectful rivals.

I also think that not only Whitebeard, but Sengoku and Garp are going to be driven out as one of the great powers of the world, and thus set the stage for a new series of players. I think Oda kind of hinted at it when Whitebeard talks with Shanks and nostalgically mentions the old days of Roger, Garp, Sengoku, and the rest. Those days, I think, are finally coming to an end and the new generation is going to take up where it left off and start a new era. I don't know whether it's going to turn out well or not, but I do think that this is the old generation's "last hurrah."

That being said, I am seriously looking forward to seeing Sengoku and Garp back in action! We didn't get to see the entire fight with Shiki (just its incredible aftermath!) which I think was just so that the full impact of their power would blow everyone's minds when they're revealed!!
:DD