I put a good 250 hours on UT3. Just recently stopped playing it. I'm now back to UT2k4 and having much more fun that UT3. Hit me up on Xfire if you want to be my game buddy or something:
I also plan to play UT2k4, until Quake Live. When that shit goes up it's gonna be amazing!
Have you seen Dark Sector? That game is incredibly realistic looking, and it's on a CONSOLE! Anyway, I agree with the 15 years statement. 5 years until it's capable, and 10 year refinement sounds realistic.