Sun will officially release Solaris 10 update 2 (6/06) today. This will only be available for download today with media being available in about a month's time. The big news about this release is the official integration of ZFS into the OS (it's been in Solaris Express/OpenSolaris for ages).
Whilst it's not supported on any of the filesystems important to the OS (/, /usr, /var, /etc) yet, it will certainly make maintaining data filesystems a dream and save people a bucket load of time and money. Why would anyone want to pay Symantec/Veritas for VxVM/VxFS when Sun has just released the best filesystem in the world (according to Sysadmin Mag Part 1, Part 2)?
If you're keen to get playing, but don't actually have a stack of disks to play with, don't worry, the ZFS developers have thought of you and actually made it possible to create ZFS pools on top of UFS. Granted performance isn't brilliant, however that's not the point. This functionality is there so you can test and tinker and learn ZFS without shelling out. Ben Rockwood has got a basic run through on how you can use 128Mb or larger files as virtual disks for testing ZFS. This is pretty much also covered in my cheatsheet.
Now ZFS is officially supported, lookout for some awesome storage coming from Sun.