Hi! I’m new here, but just wanted to add in that you can use Trillian, GAIM, and a multitude of other Jabber supported clients. Ah the beauty of open source and open standards. 🙂 Just for the record, when you add a non-gmail contact, it’ll send that person a Gmail invite. Who knows, maybe you can sway your friends away from the defunct AIM they are using? hehehe….
For the record, I generally use Trillian Pro myself, but the Google Talk client is very clean. Also, the VoIP functionality will be moved to the SIP protocol, which is also an open standard. So basically, you’ll be able to use both your fave multi-protocol IM and a standard SIP client of your picking. Very cool I think.