Lets see here:

Haye is moving up from Cruiserweight where he beat mediocre opposition at best to become undisputed champ, has a shaky defense, comes in wild and throws looping punches, has power unproven at heavyweight, and has stamina issues.....oh yeah and doesnt have the best punch resistance....

Vitali - has never been down or even hurt from a punch (spagetti legged), patient, calculating, has solid technique, utilizes the jab well, has very good power, mentally tough, size and reach advantage....

I am not saying Vitali is by any means one of the best HW's of all time but he will steam roll Haye inside 5. I think Haye can possibly win a decision if he dances, moves, and uses punch and go. The problem is Haye has questionable stamina and gets drawn into wild exchanges and he will lose this battle.....