About ZFS >V.28
Currently, ZFS encryption is Oracle Solaris 11 and ZFS V.31+ only, so if you need, you have no options. But you loose compatibility forever with all other ZFS implementations like FreeBSD, Illumos based ones (Illumian, OpenIndiana, SmartOS), Linux or OSX which are on ZFS V.28
I do not expect newer Versions than V28 that are Oracle compatible.
Its more likely that we see features flags in future, not Versions > 28 from others than Oracle.
http://blog.delphix.com/csiden/files/2012/01/ZFS_Feature_Flags.pdf
Currently, ZFS encryption is Oracle Solaris 11 and ZFS V.31+ only, so if you need, you have no options. But you loose compatibility forever with all other ZFS implementations like FreeBSD, Illumos based ones (Illumian, OpenIndiana, SmartOS), Linux or OSX which are on ZFS V.28
I do not expect newer Versions than V28 that are Oracle compatible.
Its more likely that we see features flags in future, not Versions > 28 from others than Oracle.
http://blog.delphix.com/csiden/files/2012/01/ZFS_Feature_Flags.pdf