Apple has just confirmed that its new mobile operating system iOS 5.0 will be announced at a keynote address during the company’s Worldwide Developers Conference next week.

The keynote will be presented by Steve Jobs and a team of Apple executives. Also set for the stage is new Mac OS X Lion, the eighth version of the company’s operating system. iCloud, Apple’s new cloud service offering, will also be detailed at WWDC.

The conference will feature a series of technical sessions from Apple engineers designed to help developers make the most of the new systems. It’s unlikely that new hardware will feature.

the keynote takes place on June 6th at 10am in the US, or 6pm BST, which clashes with Microsoft’s E3 press conference.

Whether this is nothing more than coincidence or a deliberate move by Apple is unclear, but it’s certain to grab some attention from its rival, particularly if Jobs decides to discuss what these new operating systems can do for games on Apple’s services.