"They can't get higher, they can't get faster"
Sure they can. What makes you think coasters can't go higher or faster? No one thought that the 200feet that Magnum XL200 had would ever be broken. Now look...you've had Millennium Force, Steel Dragon 2000, Top Thrill Dragster, and now Kingda Ka, all separated by a mere few years. Maybe you won't see the records broken as often, but nothing suggests you can't go higher or faster.