1) Campaign / Scenario editor.
While playing, I kept wishing for more, something extra, something different, knowing that I've been through the game once, and that it will end the same way. Having a Campaign/Scenario editor will make this Franchise last forever, as one can not only allow user built scenarios, but one can continue to release expansion pack style adventure modules.
That IS a neat thing however the MASSIVE amount of development time to implement, and release a semi-easy-to-use editor is unfeasable.
2) Multiplayer capabilities.
This one should be obvious with the advent of multiplayer / online gaming today. Having a network/ internet capability similar to Diablo 2 would once again increase the market. Combine this feature with option 1 and bang, you have a sure fire hit. Of course, don't lose any of the original flair otherwise you lose the game. Granted, multiplayer to the extent of Ultima Online might be difficult, even multiplayer limited to the scope of Diablo 2. Perhaps only a limited number of players per game, but then this depends on the vision of the developers and the capabilities of the testers.
If they implimented this, we would see DD2 in 2020. The development time for doing a multiplayer game is ENORMOUS.
Stick to a fun single-player game and keep MP game to dev companies that have the resources to do so.
Noting the endgame sequence of Divinity, it appears as though we are being set up for a sequel, and as such, I am prompted to write these thoughts.
Thats why I have been holding my breath to see what the next Larian project is! <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />