denniskee said:5) 8.2m compare to 6m on 10D, typically more nosie will be genrated for same sensor size. In this case, have to wait and see.
U can't really conclude that based on the spec and there are not enough sample to show that 20D pix is more noisy. I am sure Canon will do something to counter the noise issue.
Therotically, higher pixel density will produce more noise, but do you remember that when the resolution of D30 doubled to 6MP in D60/10D, the latter actually have lesser noise?