It wouldn't be to hard to replicate the wait time on a board near the centralized location. Ok, it shouldn't be hard, Disney has a problem sometime implementing otherwise mundane I.T. solutions.
I think the idea works better if you allow multiple fastpasses. It would require a little more logic in the distribution. For example, if you get a FP at rope drop for Soarin' and TT it could give you the first available time for the first ride and then the first available time for the second if that time is at least 1 hour after the window closes on the first ride, if not then it advances the time accordingly.
There are ways to make the fastpasses work better without making the system easier to game. I do like Don's idea about a single machine that gives out all the fast passes. A simple touch screen that gives you all the choices and you just touch the one you want. This would keep everyone from lining up at the same machine for EE or Soarin' and ignoring the other machines.
It has potential, just needs the details tweaked.