I'd love to see some new prefabs for PCRPG.. believe it or not, i'm sure you have a fan base dedicated enough to download a pack for the server. A simple disconnect message that stated a web address would be enough for people to want to download it. I'm sure people would be curious enough if they were still browsing around at random mods on tribes right now.
As far as expansion, I doubt you will attract many people.. you're gonna have to go to a different game to really make a social mark (if that's what you are aiming for).