--Does your employer know?

Nope.

--Do they care?

I am sure they would not be happy to discover that I am using company equipment and time to play a game.

--Would they care if they knew?

Lets hope I never find out.

--Would it be trivial to detect who was connecting from the kind of security logs most corporations take?

I am not a computer person, so I have no idea what they could find out if they decided to investigate me (although I am sure they would find something questionable). It's a pretty big company and practically everyone has internet access. I know for a fact that a lot of people goof off on IE half the day. I would think they should be more concerned with people who are participating in file sharing and looking at restricted sites (ie: pr0n).

--Anything else you'd like to share about mudding and work.

It's relatively safe for me (being a faceless minion), but were I a manager or a supervisor I would not be doing it. You never know when someone will come in with a question or annoying request. That said, I schedule my MUD time around meetings and try to block off periods in the day so I can play (while things are slow of course ).