More wheel choices? get this: Phinney’s Cannondale Slice with double-duty Mavic wheels-rim and disc brake options!
via
http://www.bikeradar.com/road/gear/article/taylor-phinney-tour-de-france-cannondale-slice-50450/
photo:
It makes a lot of sense in this scenario. They had some athletes on the Slice RS and some on the SuperSlice for the Tour. Building with disc hubs saves them buying dozens of extra wheels. No reason to make those available to the public.
Money would be a reason. They could sell those pretty well, and carve out a nice market niche.