I don't see why that would necessarily happen, because the barrier to entry for new competitors in the smartphone-app-ride-sharing industry is relatively low. Of course, it could happen if Uber ironically manages to get regulatory favors that increase barriers to entry to would-be competitors.
Agreed, except that we shouldn't ignore network effects. Drivers go for one smartphone-ride-sharing-app over another because it has more riders, and riders likewise: because it has more drivers. That can be very hard to shake.
