They should just continue making content aimed at ground mounts. After all, no-flying until cap works just fine. For all I care, they can make new questing areas similar to Isle of Thunder and the Timeless Isle. I just object against the main continent flying being arbitrarily restricted. I have no problems with no-flying until cap, even though I think there should be something like the WoTLK book that you could buy to teach your alts flying, but only after you leveled 2 or 3 chars to cap and have seen most of the content already.