"Windows driver model is so fundamentally different"
Windows File System Drivers are different from the driver model used for other devices, they are a category on their own. I do not know how difficult could be porting ZFS to Windows - but file systems after all all offer the same interfaces to users - and administration utilities will go through specific driver calls.
Anyway MS was never interested to port other OS file systems to Windows, and usually developing R/W access requires fairly advanced skills in developing such kind of software.
Biting the hand that feeds IT
