A few questions though. Node tracks V8 releases, so the first thing I'm wondering is whether ChakraCore will continue emulating V8 APIs into the future? What happens when ChakraCore adds breaking changes which V8 doesn't support?
I presume MS will be supporting most development on the engine, as they benefit from IoT Core and other applications relying on Node. If Mozilla were to do the same and add SpiderMonkey, this would likely see the 3 major vendors accelerate adoption of JS standards further. I'm more bullish on JS development into the future.
If I were to predict, I'd see Node switching to ChakraCore as its primary engine in a year. V8 has been 'we build you follow'. I know Domenic and other Google developers have helped with the relationship with Node contributors, but what will happen when MS offers a less-maintenance-prone engine? Embrace, extend, extinguish!