I am in fact the author. I do understand the conservative approach toward adopting a new framework from Microsoft. However, as I pointed out in the post, Microsoft has been moving this way since Windows 95.
The lesson here for developers is not to do what MSDN advises you to do. Look at what MS is actually doing for its own application development. In some cases, like Office, that even means having a portable codebase.
What does that even mean? Talk is cheap, show me the code.
If a DLL shipped in Vista, I can expect it will be available in Windows 8. So I might consider using it (for app code that is intended to be Windows-only) once none of my customers are running anything earlier than Vista, or maybe after MS stops providing security fixes. We recently dropped support for Win2k for example.
So new APIs, even for old ideas, aren't usually interesting to me. Wake me up in 5-10 years if you're still committed to it then.
Is this one of those considerations that cloud computing (e.g. Azure) is somehow going to make go away?