Linus added support for block device based filesystems into 2.6.20, so it’ll be interesting to see what (if any) effect on ZFS/FUSE it will have, especially given it’s named in the commit. 🙂
I never intended this, but people started using fuse to implement block device based “real” filesystems (ntfs-3g, zfs).
Looks like Ubuntu’s Feisty Fawn will ship with this as the 2.6.20 kernels in the development versions have the fuseblk filesystem showing up in /proc/filesystems once you’ve loaded the fuse module, and the fuse-utils package seems to support it too.
Update: Sadly it appears that this isn’t much use for ZFS. 🙁