Nexenta is about to release version 3.1 of NCP (Nexenta Core Platform), existing installations can already be upgraded but there are no install images available yet. NCP 3.1 is used as the foundation for NexentaStor 3.1, Nexentas latest release of their software storage appliance.
The new 3.1 version is still based on a patched OpenSolaris 134 codebase, changes in this released include an updated ZFS pool version (28), write same/unmap support and probably many bug fixes.
The 4.0 release of NCP which is currently under development will be based on illumos that contains many additional features.
NexentaStor 3.1 available now
Talks I have given
3 months ago