HAMMER2 ( http://apollo.backplane.com/DFlyMisc/hammer2.txt ) is far more interesting to me than sitting around waiting for someone to care enough about Btrfs to finish polishing it until it's ready. The world is ready for a post-ZFS file system, it's just a matter of who delivers first and with an acceptable license. Btrfs hasn't at all capitalized on the significant interest surrounding it, which is a shame.