With USADA, it's hard telling. I mean, Michael Bisbing is the MW champ, Hector Lombard was KO'd twice in a row, Anderson tested positive ...
If Fedor was clean all along, who the hell knows how he'd look now against a level playing field. I think he'd have a hard time with Stipe, and I think Brock is a nightmare matchup for him, but other than that he'd be competitive with anyone I suspect. I certainly don't see guys like Frank Mir and Gabriel Gonzaga beating him, and they're still around.