A larger variety of subdungeons is really good to hear. I like the current ones but some more that are "quest-like" (the altar ones, the one that generates zombies if you take the treasure) would be awesome.
Also I wouldn't mind an increased chance of finding the Witch. It's taking me forever.

edit: Oh, and as far as pleasing the "hardcore" crowd, I wouldn't worry - I've played NetHack and ADOM off and on for about 13 years and can win them without much trouble, and I still love this game.