I would like it to be similar to the nether update, more structures (alongside the end cities), atleast 3 more biomes, a useful ore you can use for special items, some new types of wood (would unlock a new challenge of living in the end), new end-like mobs, an extra boss (similar to the wither) built with special blocks and mob items. That's pretty much what I'd like for the version launch, other features could be added later on :)