In my time in VC++ and .NET teams, there was only one 1st tier language at MS. It was the one that existed to be whatever Windows wanted - VC++. I've not been there for about 10 years but I haven't heard that anything changed and the blog pretty much confirms that sentiment.

My advice to the Rust team: you're going to get shoved so I hope you're good at shoving back. At least you don't have to worry about stevesi (unless you're with a16z or have kids).