Actually u know what, now iv looked at it properly from the above examples, the 5d is better at 3200, but the 7d is hardly bad at all, i mean for a picture that you would print, its more than useable, very infact.
Now at ISO 6400 and above I have to say there is no more or less noise from either camera, just different, advantage 5d lost there, ( i have to say I prefer the 7d 6400, its less harsh)
Im thinking ill now have to tuck into my fav hat, not a bad showing at all, I have to say it knocks socks off my 40D in terms of high ISO performance....in that ISO 6400 doubles your shutter speed yet remains not bad at all to use.