http://www.uesp.net/wiki/Arena:Labyrinthian
I know they could just make other, new dungeons. but seeing things like this return from Arena would be nice.
EDIT: i don't want the dungeon to be exactly the same. just the same name and very similar in feel (large, challenging, puzzles and so on)
as someone says later in the thread "re-imagine it, don't port it"