I may be biased as I am a 60D owner (and have been for just about a week now), but I chose it over the T2i for:
- ergonomics (coming from a 40D, the Rebel body just doesn't feel right, and the second control dial and top panel have always made the X0D series a pleasure to use over the rebels for me)
- cross-type AF points (I shoot in low-light without flash a lot, and my prior 40D found focus in darker light than I could reliably focus manually in. It was a clear step up from my Fiance's father's 30D in low light performance, and IIRC the 30D is where the T2i's AF system came from)
- battery life (the LP-E6 just keeps going, and going, and going)
- the rest - big pentaprism viewfinder, deeper frame buffer, higher FPS, and those 1/3 stop ISOs matter, especially when shooting video (160, 320, 640, etc have slightly less noise)
Now that they've given the T2i a swivel screen, it feels more like the proper "little brother" rebel version of the 60D (and I'm guessing the next 7D and 5D are going to get the swivel screen too), but it doesn't make me regret my purchase decision. I figure the handling comfort, AF, and battery life are worth the extra $200-$300.