If you're in a flight-enabled zone, when you jump out of the water, you go into Flight Form. In a no-fly zone, you go into Stag or Cheetah Form.
It's better than going into humanoid form like we have now, IMO, except for the fact that it robs us of the ability to be a stag (without the glyph) or a cheetah (ever) in the water. They need to fix this whole thing so that we can choose between auto-shifting or having our Stag/Cheetah and Seal/Orca Forms be persistent.
I do like the auto-shift from Flight to Aquatic when diving into the water, but I hate having to use a glyph slot just so I can be a stag in a flight-enabled zone, and the fact that I can never be a cheetah in one. On top of that, they've offered us the enticing new Glyph of Travel which increases our ground travel form speed, but they made it mutually exclusive with both Glyph of the Stag and Glyph of the Cheetah.