If you are wondering what's going on in the OpenSolaris community, the best way to do that is to look at the Changelogs. You can find the latest changelogs for the OpenSolaris dev repository here:
X related:
http://opensolaris.org/os/community/x_win/changelogs/
OS/Net related:
http://dlc.sun.com/osol/on/downloads/
You can also get a Heads up (highlights of some major changes that go in) here:http://opensolaris.org/os/community/on/flag-days/
There are a few different Solaris distributions out there produced both by Sun and the Open source community. Here is a quick run down on the differences.
The OS source code is distributed at http://opensolaris.org.
OpenSolaris 2008.11 (Indiana releases)
* Based on Open Solaris
* This comes with a live CD
* It is released in a 6 month cycle with 18 month support from Sun
* Uses IPS packaging/repo
* Free
Solaris 10 10/08
* Six month updates - latest version: Solaris 10 u6
* SPARC and x86 platforms
* SRv4 packaging/repo
* Free
SXCE (Nevada releases)
* Based on Open Solaris
* Slated to become the next version of Solaris
* Updates available twice per month
* Has some additional features that Sun does not release to the Open Source community
* Srv4 packaging/repo
* Sun support not available
* Free
There are also several other Open Solaris distributions. One of which is NexentaOS, a OpenSolaris based OS topped with GNU software.