[oddvar]

That would be one way to do it :)

Problems with SIP:

* There are so multiple SIP standards (e.g. rfc 3261 vs rfc 2543)

* It doesn't support NAT (unless you do rfc5626, rfc5627 and ICE)

* Its support for ICE doesn't work well with webrtc which dynamically generates candidates

* SIP's reliability is bad unless you implement rfc3262

* We want to do messaging really well - and SIP's support for that is rather basic

edit: finally, I do agree with your "yet another standard" comment! (as per the xkcd in http://matrix.org/blog/2014/09/03/hello-world/)

Given that XMPP hasn't taken off as it could have done - and the fact that each large IM or VoIP application seems to end up writing their own version (and putting that in their own walled garden) - we think a new, well-defined open standard, together with open source reference server and client codebases can be the catalyst to create an interoperable and federated "message transport" solution for a multitude of services!