Haye is the better boxer, he is faster and I guess he punches harder. That being said, Haye can be hurt by Heavyweights (Barrett fight, Chisora fight).
Let's refresh our memory: check out this sequence - last seconds of a round in which Haye gets hurt by Chisora and the ref stops the round with 9 or 10 seconds left:
http://www.youtube.com/watch?v=cUcdG58UDls
I do know that the fight showed that Haye is better than Chisora, but nobody knows what could have happened in those 10 seconds.
Fury is a big dude, he won't beat Haye with skills, but he might beat him the way he beat Cunningham: he might hurt him with size alone.
Haye didn't look hurt to me, it looked like he was knocked off balance and nothing more. However, I agree that Fury has the power to hurt Haye. Haye has always had stamina issues, and doesn't have an iron chin... so when he tires, he can be hurt fairly easily.
Fury can win the fight, but I think he has to make it into the second half to do so. For the first six rounds, Haye should be too fast and elusive for him.