Apple has released Mac OS X 10.6.6 build 10J521 to developers ahead of the official 10.6.5 release.
9to5 Mac notes the build includes "developer support for fetching and renewing App Store receipts" to enable Mac App Store support.
Apple insists the forthcoming Mac App Store is just like the App Store for iPhone, iPod touch, and iPad, offering a range of software titles directly to your Mac.
Mac OS X 10.6.5 and iOS 4.2, which includes a major update for Apple's iPad tablet computer, are both predicted to be released in the next few days. 10.6.5 has been in developer testing phase since August, while iOS 4.2 was recently promoted to golden master status.
[Via Ars Technica]