I've already said my piece on WebKit, but Blink significantly changes that dynamic. In fact, Blink is likely to completely fragment what would have been a cold WebKit-only future because it is almost certain to evolve and implement new features faster than WebKit will, and exported to everywhere that Google code runs (Android, too). And, well, that's good news in a sense because it avoids one kind of perilous future, but it's bad in another because there won't be much of a brake on Google implementing features in Blink to make Google properties run better or even exclusively in it. Remember, that's the whole reason they made Chrome in the first place, and Microsoft isn't the only one that "embraces and extends."
Maybe it'll be Blink that eats the Web, not WebKit after all.