According to this, http://www.bitwisemag.com/copy/bytegeist/bytegeist7.html, VS.NET is all COM and C++:
"And if you think that COM is dead or on the way out, take a look at the Visual Studio 2005 SDK – released just last month, remember. It’s COM; all COM; 100% pure COM. It seems that Visual Studio 2005 is written in C++ and COM."
And I believe alot of everything else from MS is still COM and C++ like Office, IE, and even alot of the .NET Framework!