As a 50D user, my first reaction to seeing these on my computer screen after the first round of test shots was: "Holy shit, that's amazing!"
I cannot think of a single example of my 50D's pics looking this good at ISO 3200 or 6400. In fact, if I have to go to 3200 with the 50D, I generally don't shoot. With the 60D, I think I can shoot at 3200 and even 6400.
You'll need to click on the image to pixel-peep, but here are a series of 100% crops of images in Adobe Camera Raw, with and without noise reduction applied. This way you can see the noise as it is straight from the camera, and then how nicely it cleans up.
These were all shot under compact fluorescent lighting that registers about the same as tungsten for color temperature. In other words, the type of lighting that screws with digital cameras. Well, at least it did with my 10D, 30D and 50D.
It's also the type of lighting that you'll curse when shooting indoor sports. I'm actually looking forward to trying the 60D out on some indoor tennis, and maybe even basketball and wrestling.
No comparison pics for the 50D because mine is in the shop.
More first impressions from my hands-on with my 60D tomorrow.