The Apple Store is down, sparking speculation that Mac OS X 10.7 Lion is about to make its first official appearance.

It is also anticipated that Apple could announce a new line of MacBook Airs today, having held back from launching new hardware before Lion was ready.

Lion will be exclusively available through the Mac App Store for £20.99 and you will need to have Snow Leopard installed in order to be able to download it.

The new MacBook Airs could have backlit keyboards, and are expected to use Sandy Bridge architecture and high-speed Thunderbolt ports.

Macworld will bring you further updates on changes to the Apple Store when they are announced, so be sure to check back for further details later today.