I have D50. I suppose D60 is to replace it. D50 is nice, although I would of course want even better.. who wouldn't 
I have just a few things I'd like that the D50 doesn't provide.
1. A backlit LCD screen on the top, like the D70, D80, etc.
3. Expanded bracketing function beyond simply one under and one over.
3. More focusing zones.
4. DoF preview.
5. Remote/Multiple Flash Control
All of these things can be worked around so given the choice between upgrading the camera body or buying new lenses... I have to go with lenses. Better/different glass is far more bang for the buck.