I don’t know about you, but I really want that Mud Crab DLC.
In all seriousness though, some of the stuff should have been in the game at release. Like mounted combat? Probably one of the top items on Oblivion veterans’ wishlists. Spears, missing since Morrowind. That improved water shader.
That said though, just package the best of that shit up as a DLC and I’ll be first in line, like the hopeless Elder Scrolls fanboi I am.