Maybe you already know the answer to this, or maybe you're just too shy to ask, but I'm going to take a moment and try and give you some idea about why ChakraCore being open source is really cool.
Plus, if you can change NodeJS to use ChakraCore, then why couldn't you sub in another engine like SpiderMonkey or something else. It leads to more options, which leads to competition, and that is always healthy in my opinion.
2. Community Support and Pull Requests
Oh no! Not another security gap in all the browsers! What ever will we do?
Until now, the only solution would have been to wait for an official release from the Microsoft team, hoping that they had all the details they needed. Now, the team can work with the community directly and publically so that we know where things are at. If there is a security gap reported, people can find it, report it, and fix it by submitting a pull request directly to the team.
Now, my browser can sleep comfortably at night.
3. Knowing How the Sausage is Made
In time, I think we'll see more than just NodeJS, but rather Chakra become the heart of a lot of cool projects.
Personally, I'm thinking of using it as an on-the-fly scripting engine where a game object has a script that needs to be interpreted during game play, like AI or some sort of behaviour.
For now I'll probably start with getting it working on my Raspberry Pi. I have one sitting on my desk and I'm itching to get something cool working on it. Either way, I'll probably start with the Windows 10 IoT page for some ideas, or take a stab at embedding it into a project.
20-Jan-2016 UPDATE: Pull Request Submitted
In case you're interested, Microsoft has submitted a pull request to the NodeJS project to enable NodeJS to run with the ChakraCore engine. As I mentioned before: we can see how things are moving along publically because it's open source. No magic, just code.
Thanks to CaptainIncredible from Reddit and the other commenters out there for taking the time to do the proofreading that I so desperately should have done before publishing. Feedback, even about my sloppy spelling, is always appreciated.