I've always thought that I would want to run windows under Linux, thus my interest in things like cygwin has always been sort of low.
But these Cooperative Linux folks seem set on making Linux-under-windows a viable idea. After all, “Cygwin is not a way to run native linux apps on Windows. You have to rebuild your application from source if you want to get it running on Windows.” But with cooperative linux, maybe not?
Dog on its hind legs, or something cool? I can't quite tell, although it seems to me that Linux under Windows would not be nearly as robust as the other way around.