As you may or may not know, you can now buy support contracts for OpenSolaris.
Apart from the ability to make a support call, you also get access to the Support Repository. This is where we backport as subset of fixes from development system and do a lot more testing. Chris has blogged on how to point at the extras and support repositories, so I won't repeat him. What I will do is point you at a couple of sunsolve documents that may be useful in seeing what we are fixing in there.
The important one would be OpenSolaris Support Repository Updates (SRUs). In this page we list each of the updates as well as a browsable link (instructions provided on how to add the certificate to Firefox) and a README outlining the bugs that were addressed.
A link to SRU 6 hasn't made it into this page yet, but you can find it here.