I own Canon 7D for month and a half and finally found the time and took it for spin at downtown Toronto. Part of the outing was finally see how I can use the camera at night shooting. I hate to lag with tripod and using tripod for night shooting is quite an imperative. So I wanted to see how 7D performs noise-wise at high ISO 1600 and 3200. Of course it was noisy. What do you expect from the camera with 18MP on ASP-C sensor? But to my surprise things were not that bad. Smaller size photosites of course contributed to the noise, but large number of them made this noise much more uniformed and more looked like a fine grain. Most important with use of NR software image still did not loose details and did not become too "plastic". Looking at web size images it's very hard to tell they were shot at ISO 3200, but also I'm quite sure 36'x24' print will look very very smooth. Even at closer look.
So I'm quite pleased with performance and most importantly with ability of getting night handheld images with relatively fast shutter speed. Feel free comment and critique.