[phkahler]

>> The most challenging point is, as others said, the lack of the compatibility with Linux Driver API.

IMHO getting a minimal set that works is good enough to get people on board. This is still nontrivial. But for example, getting FUSE working would be useful. Even if the driver itself was not ABI compatible, it would bring functionality and someone might then aim for ABI compatibility afterward which would open even more doors.