There are UFC fighters that have been training for this all of their lives. The thing is, when I'm Randy couture's age (I'm thinking about 2020) there will be fighters that have taken training to the next level. They will strike harder, have stronger chins, condition harder and have a more expansive set of grappling skills.
For instance: I'm a 5 style grappler which is alot for modern MMA, but in twnety years everyone will have trained in 3, 4, or 5 different styles. The kinds of submissions will be greater in number, the different kinds of takedowns will become more sophisticated.
There is alot of room for improvement and it will happen. As we see the fighters of this generation become coaches you'll see their fighters fight like their teachers but with even more ability and faster strikes and stronger bodies.
Of coarse, UFC will be the top of the mixed martial arts chain because it is rapidly increasing in popularity. Also, if you watched UFC 1-10 you would notice how all the fights would end under a minute and were lopsided. Now the fights are pretty fair and last a lot longer and are more unpredictable. It's evolved a lot and will evolve a lot more and I can't wait. We also may get some world class PRIDE fighters since PRIDE is going a bit downhill. Anything can happen, Anderson joined and so did Pulver.