This sounds like a bigger change than it is. I have the same boss (Steve), I'm still in the C# Product Unit (although the debugger is for all languages), and I'm on the same floor of the same building. When Andy left, I took on two of the debugger devs as their acting manager, so even that stays the same.
The C# IDE team is now led by Mike, who previously was a dev on the C# compiler. Congratulations, Mike! I'm confident he will do a great job with that great team.