Managed is a term that specifically means that the memory of the code is managed by some runtime environment. In the case of .NET code (and WinFX specifically), the garbage collector managed the memory.
In Win32, the API is unmanaged and exposed to .NET clients through interop. To .NET clients, it is still unmanaged memory and has the same constraints as any system that has unmanaged memory (possibly of memory leaks, no code-access security, etc.) By the WinFX being all managed, the .NET folks get to use the API in a more native way, but those same API's will be exposed to Win32 folks throuth interop the other way around. The code will continue to be managed, but the calling code may not be managed (in the case of calling it from a traditional MFC app for example).
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