Apple seeded a third test build of OS X 10.9.2 (13C39) to registered Mac developers, available through the Software Update mechanism in the Mac App Store as well as through the Mac Dev Center.
– Graphics Drivers
Everyone else interested in testing OS X 10.9.2 (13C44) without being a registered Mac developer can download OSXUpdCombo10.9.2.pkg with help of: https://swscan.apple.com/content/catalogs/others/index-10.9seed-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz
Please note that I may not share direct links to unreleased Apple software here so you will have to search for “OSXUpdCombo10.9.2.pkg” with help of the above link.
Hmm. It may be me, but it doesn’t seem like a lot was changed. Only a hand full of kexts. Not even one that we are interested in.