In addition to today's seeding of the iOS 5 golden master version for developers and several associated releases, Apple also seeded the golden master 11C73 build of OS X 10.7.2 on the Mac side of the developer community.
OS X 10.7.2 includes the required components for iCloud, which will be going live to the public on October 12th alongside iOS 5. The release will also include a number of other fixes and enhancements and will bring Safari to version 5.1.1.
OS X 10.7.2 should be released to the public as we approach the iCloud launch.
Article Link: Apple Seeds OS X 10.7.2 GM to Developers