Apple has revealed that its annual Worldwide Developers Conference keynote address will not be delivered by Steve Jobs, despite the plan for him to return to work from his medical leave of absence in June.

Due to take place Monday 8 June at 10.00am San Fran time, the keynote will be delivered by a "team of Apple executives, led by Philip Schiller, Apple's senior vice president of worldwide product marketing", an Apple press release states.

As the name would suggest, a developer event, WWDC will offer in-depth sessions on the new iPhone OS 3.0, and Mac OS X Snow Leopard.

"Last June, we gave developers an early look at the powerful new technologies that form the underpinnings of Mac OS X Snow Leopard", said Bertrand Serlet, Apple’s senior vice president of software engineering.

"At WWDC, we will be giving our developers a final Developer Preview release so they can see the incredible progress we’ve made on Snow Leopard and work with us as we move toward its final release".

Steve Jobs missed this year's Macworld conference in San Francisco due to health reasons. The absence of Jobs from the keynote will set tongues wagging in the industry with speculation about his health - and when slash if he is to return to Apple - no doubt about to go into overdrive. Watch this space.