The Arena is a really nice concept, which I'd love to see alive again. I'd be very happy to help testing whenever necessary

I understand development time limitations (very well, believe me), but here are some ideas I thought I'd jot down whilst I'm thinking about them...
The spectator stands are an important part of the arena, but I'm not sure yet exactly what they would show you. At least the state of health of both participants (similar to what you see in the prompt from the 'watch' command perhaps?). You also probably want to see the casting of spells (as you would if you were in the same room). Now it would probably be more work, but round-by-round "X's massacring slash tickles Y" would probably make them feature pretty complete. There are 2 viewing stands... perhaps one could show you the perspective of one player/team and the other from the other side?
Related to scoring... there's a book on the shelves in the City Archives (yes, someone reads them

where it would be handy to record events.
Something I haven't seen proposed is if there could be a prize put down (not necessarily from an immort) which would automatically be granted to the winner upon success.
Dead PCs could be automatically recalled to the prep rooms for revival (and in case of a team match presumably *not* allowed to re-enter).
Also I think making the arena autonomous is quite important, lest it become (another) time sink on the already busy overlords

I enjoyed using it last time (though I lost), and it would be fun to brush the dust away again (read: I know how to parry now

).