1. Dual Wielding, complete with two button action. (see Unnecessary Violence for good examples)
2. 10 x better stealth game (thievery, assassins skills, sneak attacks, etc, etc). And yes, go all out like the Thief Series
-Tying in with this. Let's see some of the things I tried to accomplish in Stealth Wars: Some thieves and assassins sneaking up on you.
4. A good companion system (monstrous pets, friends, lovers, a nagging wife, all the above, etc.)
5. Flaming/glowing/particles for enchantments! If I've got a fire enchanted sword, I wanna see flames on it dang it!