This past week Google made several changes that are part of their ongoing disruption of telecommunication. First, they announced at Google I/O that they were unifying their various real-time communications services (Google Voice, GoogleTalk, Google Messenger, Google+ Hangouts) under the "Hangouts" brand - and they also announced two "Hangouts" apps for iOS and Android, marking Google's entrance into the "over-the-top (OTT)" app space. Google also connected Google Voice to Google+ Hangouts so that you can now receive phone calls to your Google Voice number directly inside of Google+.

On the negative side, they have removed support for XMPP.

For more info, see: http://www.disruptivetelephony.com/2013/05/you-can-now-call-into-google-from-regular-phones-google-connects-google-voice-to-hangouts.html