Mac OS X 10.7, also known as Lion, will have a dramatically redesigned user interface, according to reports.

TechCrunch claims that Apple is already using the new OS internally - not just for internal testing, but widely among Apple staff.

It substantiates this claim with data from TechCrunch usage logs, which suggest that there has been a big surge in the numbers of visitors to the site that are using Mac OS X 10.7.

The site also claims to have heard from its sources that there will be a UI overhaul, though exactly what this will entail is unclear. However, it anticipates that a developer beta programme should begin soon.

There are a number of things that we do know about Lion - it was previewed back in October 2010, after all. Back then, Apple promised a summer 2011 launch and that some key iOS functionality would be incorporated into Lion.

There will be more advanced use of multi-touch gestures; apps that operate in full-screen mode rather than in windows; a Launchpad feature, similar in functionality to the iPad's home screen; and a feature called Mission Control that combines elements of Exposé, Dashboard, Spaces and full-screen apps.