I do have one question. Why, exactly, do you think that this sort of approach is likely to be easier than doing what Apple did and simply exposing a Posix API that is actually useful?
Because, even if we could get a great POSIX experience on Windows, it leaves out Windows developers.
One of my goals is to get Windows developers in the OSS game.
On top of that, there is a hell of a lot of non-POSIX open source software on Windows that needs fixing too.
Look at it this way: Would you respect someone who told you the best way to get FireFox running on Linux was to use some sort of Windows emulation layer... Like WINE? no, because FireFox *can* compile for Linux. Same thing with nearly all Open Source I encounter. I want to get the OSS quality and experience on Windows to exceed commercial developers... it needs the most love.
Like I tell people:
Working as an open source software developer at Microsoft is like being a preacher in Vegas. I figure I'm in the single most important place in the universe that I can be.