We just saw Fedor lose, for the first time, for real. We also saw Cyborg beat the shit out of another overmatched opponent.
I think the two primary fighters just mentioned are representative of a standard. Fedor is old school, dominated Pride, and was untouchable. Cyborg is currently dominating women's MMA in a similar fashion. The time will come, however, when she will be surpassed, and appear to be inadequate in her abilities, with respect to an as yet inexistent level of competition.
Maybe this is beating a dead horse, and if anyone else has already said as much, regarding the contents of this post, then props to you.
My feeling is that we are truly witnessing, in real time, the evolution of the sport. Some people want to cling to the past and try to deny that their fighter has been surpassed (I'm not just referring to Fedor here), but the truth is, fighters are bigger, faster, stronger, and more accomplished than ever before. Those not able to keep up will be subjugated and forgotten as the new crop of elite athletes emerge.