Hi,
are there any relevant features for you on the 60D or 7D that your 50D has not? If I had a 50D and it was working proberly I would not upgrade it to newer APS-C size sensor camera at the moment.
The 60D has even more disadvantages:
- batteries and batterygrips that fit on older xxD cameras, like 40D DO NOT fit anymore on 60D
Robert