i think that a game server would be a FANTASTIC idea. The way i would do it, is get a new domain like Clanserve.com (just came up with that on the spot, dunno if its real or not) and then you could have people hosting their clan websites on that, because i no from personal experience, alot of clan hosting sites have alot of popups and ads, which x10 just doesn't have, also i found that alot of them were too n00b friendly and only let you use a few templates that they had setup already, where most people can setup a clan website in just a few hrs. And the advantage of a clan site is that you don't need much web space at all.
To address the problem of the teamspeak server consuming so much bandwidth, which it does. You may be able to reduce the quality or kbs of the voice, making it consume considerablely less bandwidth. I havn't seen the server for TS, only ventrilo, so i not sure if it could be done but that would be an option.
And i think that it would draw ALOT of people to x10s site.