http://www.tokbox.com/blog/firefox-hello-mozilla-enhances-op...
But taking it a bit deeper, this is all part of Telefonica's strategic partnership with Mozilla to market phones running Firefox OS.
That is what Telefonica might be doing -- providing a default registration service.
Also because of funky routers and NAT rules, even after the initial session is set up data/audio might not be going through, so then you need STUN or TURN servers so Telefonica might be providing those as well.
Anyone doing WebRTC seriously will need to run a fallback centralized pairing service to get around the wacky real world network topology and setup a successful p2p connection. In some cases, you need a dumb centralized pipe to connect the peers.