Goodness me, there's a lot of MS bashers / Rust deniers out there today!
It Really is Time to Move On.
Setting aside concerns about staff heritage, these days one would really struggle to justify C/C++ to write a new OS in from scratch, as opposed to choosing Rust. Ultimately the only thing stopping it is the opinions in old dogs not willing to learn new tricks. Other concerns such as the stability of the language are merely temporary barriers, not fundamental no-gos.
The fact that MS is thinking of going the way of Rust is interesting; if they do it wholesale, their kernel (and whatever else they write in it) is going to become very solid indeed. That would start making things like Linux and the BSD look positively antiquated. Whilst those communities would be spending a lot of time making sure there's no memory mis-use in their code (and there's likely shed loads), Microsoft would be concentrating on eradicating functional bugs.
Round the bazzars, there has been some loose talk of re-doing Linux in Rust. Because the C interop isn't too bad, you'd be able to do it bit by bit, there's no need to do it one big bang. There's also a bunch doing a fresh OS, called Redox, looks pretty good.
The Next Generation of Programmers
The real killer will be if universities, at least those still teaching systems languages like C/C++, dump it and pick up Rust instead. This has happened before - Java killed of a lot of C/C++ tuition. This happened simply because it was easier to teach Java, not especially because Java was superior or anything like that. Rust might just finish C/C++ off in the educational sector. In a few years time the supply of graduates who even know what C/C++ is could dwindle to zero.
Companies (who have a hard time recruiting already) will be faced either with very lengthy and expensive training to get newbies up to speed in C/C++, or the quicker-to-learn Rust instead. Most of what you learn with C/C++ is not the syntax and libraries, it's avoiding all the ghastly pitfalls littering the language reaady to trap the novice programmer. With most of those eliminated in Rust, you're left with just learning the syntax and libraries. That's far easier and quicker.
Develop, or Die.
So for all those dyed in the wool C/C++ stick-in-the-muds, it's probably time to start worrying about becoming obsolete. You have to ask yourself, what's better? To be a leading light in the adoption of a better and more sustainable language? Or to grudginly learn it when it's become unavoidable, and get paid the same as a fresh faced graduate straight out of college? All that valuable and renumerative experience of how to avoid pitfalls in C/C++ is going to count for sweet F.A. if Rust takes off.
Either show the money in which direction it should be going, or try and catch up when the money has made its own mind up.