In an ideal world, this need not be a problem; we typically see ZoL releases supporting new kernels well before those kernels hit Debian backports. Unfortunately, however, there is a chicken-and-egg problem; the Debian package maintainers need to be confident that the zfs-linux packages will work with both new and existing kernels (on all supported architectures) before a release can be made, and the BPO kernel maintainers occasionally include forward patches from other kernel trees. It's not impossible to make this work, but it is labor-intensive and has an unpredictable schedule.
Colm
