I have the 7D. And, having upgraded from the 350D, I can confirm that it's an amazing upgrade. It is a different beast entirely.
I also have the 50mm f/1.4, and I can tell you that the two go VERY WELL together.
Unfortunately I cannot comment properly on the 60D but from the outside, although the swivel screen is nice, I would definitely miss the AF of the 7D as well as its continuous shooting burst rate of 8fps (I love airshows).
The 7D is built like a tank, and I'm pretty sure that if push came to shove I could use it as a hammer to bang nails in. An unexpected benefit of this is although it's heavier to carry round, when taking pictures I find the weight helps me hold it much steadier than with a lighter camera (I really notice this when I go back to my 350D from time to time).
The low-light abilities of the 7D are pretty good. Whilst you do get noticeable noise when pushing it above ISO 3200, for the most part it's very good indeed. If you are reducing the files for displaying on-line, then 3200 or 6400 will work fine for you, but at 100%, even at ISO 2000 noise is well controlled, and I have no hesitation in going to 1600 if needed knowing that I don't have to worry about it at all.
I love using it. Also, the price of it has come down drastically since it was released, and that is the only sting for me. I got it soon after it came out, at £1699, but now I've seen it as low as £1200! The 7D is still more capable than most other cameras out there. At over two years old now, it's still a superb piece of kit and very, very capable.