Personally, I am hoping we get a dragon themed class like we see on the timeless isle. It showed a tank, healer and a dps. Though I do feel we need a new ranged class desperately. We have had no ranged additions since the game came out. Even lost 1 ranged spec.
I feel adding a 4th spec would accomplish a lot too. They had a great way with gladiator dps. It was fun and unique in how it dealt damage and how it was presented. Only downside it had was that it didn't scale well and they basically gave up half way through the expansion on it as a result.
We need things like that to get this going. More ranged is also always a plus.