As the go-to browser toolkit, WebKIT has been around for a long time and for the most part this open source project is owned by Apple with large contributions coming from Google ala Chrome.
In reference to WebRTC, Apple is really not saying or doing much around WebRTC (at least not publicly), so it should come as no surprise that Google might feel the need to drive innovation into their new Blink project. Obviously WebRTC is not the only motivating factor here but it seems likely that it played a part.
This is probably a good thing, Blink now provides an alternate solution to WebKIT and will seemingly move quicker with Google driving. It could also create fragmentation, which could (for some) be a bad thing. It also means there there is now another critical component of WebRTC under Google’s control, not saying that is bad, just sayin..
At any rate, it begs the question “Where the heck is Apple?” It would be nice to see this mobile market leader taking more of a leadership role in the development of WebRTC. They have been somewhat more vocal recently around the MTI video codec debate in the IETF but aside from that they have remained relatively silent. One thing seems certain, it will be up to Apple to maintain WebKIT now that Google is focusing on Blink.