I saw that. When I heard Kimbo was going to fight Nelson, I looked at it again. I don't think the white guy was fat enough to be Nelson, and the black guy could easily be Demico "Rashad's Big Older Brother" Rogers.
BTW guys if you frequent MMA.tv you may have seen a thread where images are taken off the TUF intro and there it looks like a black guy is beating down a fat white guy (its amazing how Nelson is a pro fighter but still manages to look like a fat ass that never stepped in a gym his whole life). Its very unclear but the arguement can be made that its from the Kimbo-Nelson fight. But it could also be some other guys,