I hear a lot of confusion about this. I don't know why TechCrunch said what they did, but by all accounts, there is no golden master right now. This is just a developer preview. After this there will (probably) be betas. And after that there will eventually be a golden master or two.
Apple uses the term "golden master" uniquely, but it's basically what most software companies would call a "release candidate". The goal is to make only one RC. You release a RC build when you legitimately believe that the product is complete and this is the build you plan on releasing to the public. It's the last phase in testing. You let your testers try it out and see if there are any show-stopping flaws, if not, the "release candidate" becomes the "release".
When the GM is ready, it will be released to developers and labeled as such, and the public release will follow very shortly after. I don't know why TechCrunch is claiming this is an "internal GM", maybe they know something I don't, but as it stands it seems they are just causing confusion.