Yesterday Pawel Jakub Dawidek (PJD) announced his ZFS on FreeBSD project. He has done a tremendous amount of work for only 10 days. If you or your company has the resources to help/sponsor PJD on this project that would enable him to spend more time on ZFS on FreeBSD.
It looks like the folks from Sun are open to patches from Pawel’s efforts. While having ZFS on FreeBSD would be awesome, keeping efforts in sync will be a big deal going forward.
As a side note, the ZFS on FUSE/Linux is still moving ahead.