Which would be a very good thing, for we might witness the raise of a fresh new Mozilla and a new Firefox kicking ass, instead of watching year after year the decay of the current ones.
You give the world too much credit. If firefox jumped to blink, we'd just shrug our shoulders. A few of the hardcore would move to IceWeasel or PaleMoon, but the majority of people, even developers, might shake their heads a bit, but wouldn't really care all that much.
There was an alpha product based on Servo in June this year. Servo is nowhere near being done enough to be an actual product (the alpha was a tech demo).
Some Servo components are close enough to being "done" that we're considering sharing them with gecko.