AppleInsider and 9to5 Mac have both received word that Apple is planning an "overnight" on July 13 in its retail stores. Such retail events usually precede major product launches, with store displays being refreshed and managers being trained on the new products. Following the July 13 store refresh, OS X Lion is expected to be released to the general public on July 14.
According to AppleInsider, Apple's retail stores will also be upgrading the RAM in several display units to ensure that Lion demoes smoothly on them. Their source also claims some customers will be invited to come to the Apple Store and download OS X Lion there so they can get on-site coaching on Lion's new features.
The sites also claim the long-awaited MacBook Air refresh will take place soon after Lion's release to the general public, possibly as soon as a week later. AppleInsider had previously reported that the new hardware was ready to go some time ago, but Apple decided to freeze new hardware shipments for the time being so all new Macs could ship with OS X Lion pre-installed.
OS X Lion will be US$29.99 and exclusively available from the Mac App Store. The current developer-accessible version is GM Seed 1.
Apple MacBook Air 13-inch (early 2015)
Apple OS X Yosemite