I dont know if it's fake either, i mean people have been getting these things for beta testing in xtremesystems. But it's probably fake because all they had to do is just use one of the pics from xtremesystems and there they go, proof of kentsfield.
There is really no way that is actually legitimate. If you actually recieved a quad core for beta testing like some poeple over at XS, would you really put that thing up for sale??