The current lineup is...
E-ticket ride
C-ticket ride (might be changed to a walk through)
Flex restaurant (counter service by day, table service at night)
Merchandise
Night time show (not necessarily Avatar themed)
Enhancements to the rest of the park for evening hours
We've never really seen much confirmation on the specifics of any of them, which may be because the situation is still fluid. The E-ticket is supposedly far more exciting than a Soarin' type ride. The C-ticket might or might not be the boat ride from the leaked plans; it might be cut down to a walk through (imitating Pangani and Maharajah) but with AAs of animals from Pandora. I've never seen much information about the night time show, though previous to this, people had talked about a World of Color style show coming to DAK, which would require a new body of water to be developed since the existing ones don't work.
There was also talk about a night time parade at some point, but that has seemingly been cut.