yes. I see sometimes advantages (more detail) in small to medium size prints 50D vs. 30D, same ISO (much more advantages in large prints). But this is, I think, due to resolution, not ISO noise.
I did, however, so far not recognize any noisewise difference in same small size prints 50D vs. 30D. Or 1DMkIIs or 700D. Maybe I am half blind, but to me, good shots out of this cameras look in print all the same.
So far, the photographic magic of pixel peeping escaped me. But of course I respect if another person is all focused on it.
Some of my Photographs: http://photo.net/photos/various%20things