I can't see us ever returning to the 24th Century trek, and if we do, it will be an iteration beyond our imagination for a generation of trekkies yet to be born.
I forsee the movie series running to four or five installments, with the last one being a bit rubbish, but during this time there will be an animated series with episodes of a quality ranging from mediocre to inspired leaving fans to argue about their inclusion in the updated encyclopedia. Trek will then disappear from view for a while until its time for another renaissance, but this time, it will be a new crew on the Enterprise visited occasionally by the film cast. If the new series is a success, it will spawn a spin off series of its own and a few movies. Eventually though, the franchise will grow stale and demand another reboot, though by this time, the economics of TV will have changed and the best we can hope for is low cost webisodes available only by subscription.
What ever happens though. TNG had 7 years, 3 spin offs amounting to another 18 seasons and 4 movies. Its been done to the extent that it'll never need re-doing.