Well, if you're asking me to limit myself, we're already starting to have problems. The point of the telepathy framework is the ability to provide a wide variety of clients to a single sign-in. So I would want the extra VoIP functionality provided with the Beta (Sofia-SIP), full Farsight (video/audio streaming) capability, plus the Haze plugins (ICQ, MSN, AIM, etc), and of course, link local (I think it is called "salut" in Telepathy). You should be able to scan the local WiFi network and see other people in your "neighbourhood" on your chat service...

But just because I didn't mention one of the Telepathy-supported components doesn't mean it shouldn't be included. I guarantee there will be lots of people who would want the IRC plugin, "idle," included too.