Here's my thoughts on what i loved about Div and what should remain:

1) Just one hero - no parties or such - for some reason i find having a party runnin round after you really cumbersome and iv even tried playing some games
(like neverwinter nights (impossible) and dungeon siege (hard but do-able) with just one character because of this.

2) Free-Form - i like being able to go anywhere i please and do side quests in any order i like - it adds to the replayability factor.

3) Teleporter stones - or some similar method of transportation - it was fun using the stones to help me thieve peoples shops/houses - especially so i could get that big new shiny sword that i couldnt otherwise afford

4) Free-Form Character Skills/Attributes - i love the idea that i can play a barbarian slayer but also use some magic if i wanted to - but i wasnt forced to use certain skills or limited to anything.

5) Lots to see and lots to do - i like the vastness of it, but it's also good that the villages arent too big - too easy to get lost/miss out stuff if they're too big.

6) The humour! - Granted some of the humour is hit and miss but i love little things you can find out via reading or exploring that just make you laugh - examples from other games like morrowind are where you find a journal of a dead adventurer that is obviously a homage to Indiana Jones.

7) Alchemy! Making potions and upgrading your weapons was also kewl. I'd like to see this kept and improved upon if possible.

I think that's it for now.