Kate Gregory showed that C++/CLI is the best and sometimes the only (allowed) language to access all the Vista features.
In short:

• Only in VC++ you can access all Vista features
• Some Vista features are easier to access from VC++
• Some Vista features are only accessible from VC++ 😉
• Some Vista features must be written in native code (like PropertyHandler, ThumbnailHandler)
• C++/CLI is a “natural” and “must have” tool to fully develop for Windows Vista
• C++/CLI is the best language for InterOp