This is primarily addressed at Orrin, but it's a public post as I feel it may interest other people as well.
In the last few days I've seen two separate muds advertising an embedded copy of FMud as a Facebook application. I'm not sure how effective this is at bringing in new players, but it strikes me that a more graphical interface would work much better at targeting Facebook gamers. In fact I'm rather surprised that Maiden Desmodus's customised client hasn't been made available as a Facebook application.
In the past you've talked about using ATCP to draw graphical bars. Have you had any more thoughts about this? What about extending it to other things, such as a background image, the buttons, or the map?
ATCP would also provide an easy mechanism for passing the user's IP address to the mud, for those who wish to collect such information.