The cat's out of the bag: During Apple's third quarter financial earnings call, chief financial officer Peter Oppenheimer announced that Lion would debut this Wednesday on the Mac App Store. The OS update will cost £21.

Lion is the seventh iteration of Apple's Mac operating system, OS X, and brings a host of new features to the Mac, including window management utility Mission Control, app organiser Launchpad, full-screen mode for applications, state-saving utility Resume, Auto Save and Versions, AirDrop for local file sharing, a whole slew of updates to existing Apple applications, and over 250 other features.

Lion will be available Wednesday exclusively from the Mac App Store for users running OS X 10.6.6 or later using Core 2 Duo systems or later. Users on Intel Macs powered by a Core Solo or Core Duo processor will not be able to run this version of the OS.