Updates on the thread:who won ?
I think this will be closer than a lot of people think. Yes, HU NLHE is Polk's game. Yes, the majority of hands will be online, which is Polk's game, but I don't think people give Negreanu credit for his ability to study. It's not like he doesn't have a wealth of knowledge and experience. He will know what he needs to study and there will be a lot of material available for him to study Polk's game.
I would still make Polk the favourite, but write Negreanu off at your peril...
Oh...I feel more than a little silly reading this thread. I hadn't actually known that Polk was considered that kind of really really good. I'd been thinking that people just wanted to root against Daniel because he's become much less likeable for reasons I might have known about at some point but totally lost track of by now.
For my part the whole rivalry between them seemed unbelievably petty on both sides, at least in the talk before the challenge was accepted.