Depends, I think if Rogers improves his wrestling enough to use it reverse and stop a takedown or his judo throws, he's got the KO power. We didn't get to see his improvements in his last fight because he knocked out Arlovski in about 20 seconds or whatever it was. He's got a lot of size on Fedor, so we'll see how that works out.
The only criticism I have of Fedor is that he hasn't fought the toughest competition out there, especially in recent years. Be that his fault or his handlers fault, I don't care. He's fought maybe 2-3 top notch guys in his career, Nogueira 3 times, and Mirko Cro-Cop (who in his prime was one of the best kick boxers ever in MMA).
He's a top 4 pound for pound fighter in the world, but I'm not sure I'd put him over St. Pierre, Anderson Silva, or Lyoto Machida, only because those 3 guys have been facing top level competition their entire careers.