Message Buffer & Colour Coded dialogue
I don't know about anyone else but I'm really missing the message buffer from ADOM.
I'm finding that half my inventory has gone missing, or my stats have fallen through the floor, and I can't even work out how it happened.
I think it would be really useful if positive messages were typed in green and negative ones in red. So when you're in combat you can quickly pick out the important information.
It might even be useful to let people customise the dialogue. So you can pick what messages are ignored, which are displayed and which are important enough that you want to freeze the game until acknowledged.
Item destruction and stat shifts are the things that I most want to know about.