Ars Technica has a review of Open Solaris 2008.11, the latest release from Sun.
The strongest point of this release is the integration in the environment (notably through Nautilus) of ZFS, the Zettabyte File System, which is a next-gen file system supporting lots of nice features, such as storage pool, transactional file system updates and advanced snapshotting. It is a contender to
MurderFS ReiserFS now that Reiser‘s in jail for murder. ReiserFS is one of the very nice file systems, but its future is uncertain, which is a major bummer for me as all my Linux boxes are using ReiserFS. ZFS is its most serious contender given its features, at least if one gets around the fact that it is not released under GPL but CDDL.