I think Haye is a capital Tosser (though I can't say I know him), but Smash bought up a good point in that, wether Haye can win or not, he sure is in the game to fight the best opposition and isn't a ducker which we see so often, he brings the fights the fans want to see.
IMO he has a punchers chance against Wlad, and that's all. I'd give him a good chance against anyone else at the top at the moment, the type of fighter he'd really struggle with is a heavy version of a tough come forward fighter like Mormeck/Fragommeni since the Heavyweight version should be able to take the early punishment and finish him off, but i can't think of any of the current crop who fit that description. IMO the blueprint (for a guy of without a massive height advantage) to beat Haye is to take away his punching room and keep him fighting at a pace.