Microsoft has announced a big developer event in September, so speculation is now rife that we'll see the first public beta of Windows 8 revealed then.

The newly announced Professional Developers' Conference (PDC) is set to run from 13 – 16 September in California.

A September 2011 reveal could point to a full retail release around September 2012.

This potentially imminent beta also means we could see some prototype Windows tablets surfacing towards the end of the year, although the tablet-specific Windows OS probably won't be around until 2012.

Screengrabbed

Screengrabs of the Windows 8 desktop have also allegedly been pilfered from Microsoft's top secret vault and posted online.

Unfortunately for Microsoft, one of its many employees failed to adhere to the desktop background which says "shhh… let's not leak our hard work".

Windows 8 leaked desktop

It's an early build, so there's not a great deal to see; and it's not looking hugely different to Windows 7 at this point.

Via SFGate and WCCFTech