Google Talk, or, no news is big news
Indeed, it’s just a Jabber server. Anyone can run a Jabber server. There’s nothing special about what Google did, here.
The big news about this story, in my opinion, is simply that Google are endorsing XMPP.
The fragmentation between IM services and the segregation it forces has been bemoaned for years, but no significant inroads have been made. The third-party, multi-protocol clients are still fighting an uphill battle. Jabber, in contrast, allows users to add JIDs from other Jabber servers to their roster, provided both servers are configured to talk to others. If XMPP actually got widespread adoption, IM could become decentralized the way email is.
Unfortunately, Google’s server won’t talk to other servers. At this stage, it’s just for Google Talk users to talk to each other. But if Google’s move into this space can widen the installed base of XMPP clients and raise awareness enough that everyone not only can, but wants to and has incentive to run a Jabber server, then the walled gardens of the big providers will eventually come down. That would do the world good.
It is also inevitable if Google Talk achieves any widespread adoption, so I can’t imagine that Google will keep to themselves forever. They will probably open up the server eventually.
As for Ars Technica’s dismissive article, it is unclear what exactly it is that they tested. XMPP as such contains support for file transfers and excellent multi-user chat facilities. But the server has to have those features enabled, and not every client makes them available. If these features are just lacking from the Google client but enabled on the server, they would be available with any good non-Google Jabber client.