Adobe has released the stable version for Flash Player 11.5 and AIR 3.5, and the new revision incorporates several new features, as well as a set of repairs designed to improve overall stability and functionality.
Among the new things there is the possibility to package multiple libraries in an ANE (AIR Native Extension) for iOS.
Developers now benefit from improved debugging workflow, as they can view a stack trace from release builds of Flash Player as well.
As far as repairs are concerned in the new release, these address issues such as failure of background audio on Android devices or crash of the player when navigating back and forth Flash content in Internet Explorer. The full list is available on this page.