I would like to see actual implementation of 5th edition rules.
And a six character party.
The first one was promised, so do deliver on that. The second one is just about get the fun part of the game up to par. It will make combat less punishing for misses, it will go quicker and make for much more interesting party composition.
If they also updated with less divinity surface, less divinity barrels, and less divinity arrows, I'd be very happy about this product.
In short, any update that makes the game less DOS3 would be awesome.