Originally Posted by
HillRider
Look up "Shiftmate". There are models that will let you do nearly any mix-and-match between Campy and Shimano components. I've used them to match Campy 10-speed shifters with Shimano 9 and 10-speed cassettes and rear derailleurs and Shimano 10-speed shifters with Campy 10-speed cassettes and rear derailleur. Nearly any permutation is possible and they work very well.
I guess the reason I didn't suggest it is that it becomes part of the drivetrain. So if he's got 2 wheelsets, one Campy and one Shimano, then the shiftmate would only offer the correct pull for one. This makes wheel swaps impossible.
However, nice used Shimano wheels are more common, so I he got the Shiftmate, he could just get extra Shimano wheels and be happy.
I've got two sets of Campy wheels for my bike, so I hadn't thought about it that way.