Could Apple be readying a release of Mountain Lion to coincide with the launch of iOS 6?
New features of Mountain Lion will include:
Better Facebook integration, including a single sign in; Facebook as a sharing option; Facebook friends’ contact information and profile pictures to appear in Contacts; Facebook notifications in Notification Centre.
Game Centre updates to include: Sharing scores on Facebook, Twitter, Mail or Messages; Facebook friends included in recommendations; Facebook Like button; Challenges.
Also: Power Nap support for late 2010 MacBook Air; iMessages from phone numbers appear in the Messages Mac app; add Passbook passes from Safari and Mail on your Mac; shared Reminders lists; Facetime calls sent to phone number will be received; new sort options for Notes; more language support for Dictation; a French definition dictionary; and more.
It is also thought that the update will improve battery life. Owners of MacBooks, MacBook Pros and MacBook Airs began reporting battery life issues shortly after Mountain Lion launched in July. According to user reports, battery consumption is considerably faster than before the upgrade to Mountain Lion, with a resulting shorter battery lifespan.
Macrumors has more information about the coming update.