We announced a new communications product, Hangouts, in May 2013. Hangouts will replace Google Talk and does not support XMPP.

What is Google Talk?

Google Talk is an instant messaging service built on open protocols. Google has opened its IM service so that you can hook your own client applications into the Google Talk service, or you can connect (federate) your service with ours.
Jingle is a family of XMPP extensions that make it possible to initiate and maintain peer-to-peer sessions. Specific Jingle extensions support voice streaming, video streaming, and file-sharing sessions.
Extensible Messaging and Presence Protocol; an IETF standard for instant messaging. XMPP was originally called Jabber, and the XMPP enhancement proposals (XEPs) were previously called Jabber Enhancement Protocols (JEPs).