There’s still approximately 11 months of early access to go (or maybe even longer), so quite a bit of content will still get added. ;) Stuff like the actual end-game, event system, deeper quest system and legendary items all haven’t been implemented yet. There are also loads of details that will get tweaked or put in to as time passes – like the goblin faction, dungeon locations, improved AI, etc.
Early Access has so far mostly been focused on doing bug fixes, but I think that we’ll eventually see the number of updates decrease and in turn see more content get added.