50D - Too Much Camera ?

From what I understand (?) , the 50D out resolves many non L zooms, such as the 17-85, 28-135, 70-300, etc (exc. 17-55 and perhaps the 10-22). If this is the case, what is the end result in coupling this camera with one of these lenses?

Will images from the 50D, as opposed to those from a 40D, coupled with the mentioned lenses and given the same shooting conditions, be of lesser or perhaps the same, or even worse quality (sharpness, contrast, color, etc.). Noise not too much of a factor for me, as I generally shoot under 400.

I would appreciate hearing from those who have used both the 50D and other xxD cameras with these lenses.

Thanks