While ZFS at v28 has proven to be both a lot of fun and very useful for many of us, the updates since (first available for general use with Solaris 11 Express last year I believe) add a few really nice features
Careful, they've also abruptly removed a few really nice features in later versions that have caused major headaches for me and many others. For example the "aclmode" property was completely removed from version 31 - completely breaking a lot of deployments that made extensive use of ACLs. Version 33 released today with Solaris 11 thankfully restores that feature after significant outcry from affected customers (I believe Illumos went forward and restored it on their own as well) - but the damage has been done in a lot of cases.
Just a word of warning to be very careful before running "zpool upgrade" as Oracle's philosophy on backward compatibility and stability of existing features seems to be quite different than that of Sun.