Gnome 3 added integrated support for online accounts including XMPP. As we already have a DBUS connection via GApplication API we should be able to use Gnome Online Accounts for XMPP (GTalk) login via OAuth2, which is needed to access online game catalogs and establish a connection with a game service. Currently only Google supports this.
To complete this task, send an XMPP message to a test account whenever GnomeSoy starts. Future GCI 2013 tasks do much more with XMPP, for this we just need the basic connection working.
While working on this task you should join and remain in #CopyleftGames on Freenode to get help, feedback, and guidance from mentors and other developers. Code updates which may affect your work are also announced here as they happen.
When you've done, commit your work and post the resulting changeset url to this task.