I think Arlovski's definitely got the technical stand up to beat Fedor via cut or KO, I don't recall Fedor ever facing someone with the boxing skills of Andrei.
However Fedor is a very smart fighter and always has a good gameplan. Plus Arlovski's gonna have to be very elusive as he doesn't have the chin to hang power wise with Fedor. He was on his way down via a jab from Rizzo before the second punch landed in their fight.
Either way it's gonna be an awesome fight, could go either way but I'm leaning towards Fedor.