This project has moved real slowly but keep remembering how often Eich referred to this as the most important aspect of Mozilla.
I would be unsurprised if Google were quietly doing something similar, of course, particularly with Mozilla having been quite open about this project for several years.
That's a bit apples to oranges comparison, no? One thing Servo didn't touch is JS Virtual machine, it's still SpiderMonkey. Rewriting that AND the layout engine would be suicidal.