Google are using a recognised standard (namely XMPP), rather than doing a Microsoft and inventing their own standard. So that means that I don’t have to use their client (or wait for a Linux version), I can go ahead and use my existing client and use Google Talk and my jabber.org account at the same time. Oooh, warm fuzzy feeling – open standards are good.
The catch (for there is one, of course) is that google aren’t allowing messages from their server to any other server. Normally jabber servers can talk to one another, so that you can pick any server (or run your own!) without having to worry about which server your friends are using. Google have made themselves an island, cut off from the rest of the jabber network, and are talking about creating a federalised network of trust or some such nonsense. So they have basically leveraged XMPP (“hey, we hardly need bother writing a client”), whilst turning their backs on the idea behind open messaging. So I have my jabber contacts, and my Google Talk contacts, and never the twain shall intercommunicate. Shame.
Hopefully Google will smell the roses and open up s2s links, but I doubt they will.
(gravitystorm at gmail dot com (until I get bored of Google Talk), or prefarably andrewjrallan at jabber dot org )