I just got an email from Apple asking me to check a few of my reported GL bugs in OS X so that I could confirm for them if they are fixed or not..
So it seems they have consolidated OS X GL as it stands for Snow Leopard, but that's about all.
I am surprised that GL3.x has not been adopted yet, and obviously no-one has been able to discuss much of this prior to the NDA being lifted. But I presume this may have something to do with OpenCL being integrated. Perhaps someone decided it was too ambitious to try and change all that underlying code as well as integrate Grand Central and OpenCL.
One thing that is worrying about all this, and I have not done any real world testing yet myself, is that the initial GL benchmarks on some machines seem to be less exciting than they were on 10.5.. It's almost like some GPU bandwidth is being used right off the bat by Grand Central. I really have no idea if that is the case, but find it strange that GL benchmarks are different between 10.5 and 10.6 on the same HW, with the slower results being returned in 10.6. That's not really something I am happy about (if it's the case) being primarily involved in writing GL code that performs as well as possible on the available HW. I hope that something is borked with the benchmark apps people are using...