The Worldwide Developers Conference keynote will begin Monday, June 6 at 10 a.m. Pacific Time. Apple confirmed that it will show off iCloud, “Apple’s upcoming cloud services offering.”

The Cupertino company also announced today that Steve Jobs will return to the stage to present Mac OS X 10.7 Lion, iOS 5 and the above mentioned new iCloud service.

A major new feature of iCloud is expected to be a music streaming service that will allow users to access their music library from any Internet-connected device, like an iPhone, without the need to save music on the device. It is expected that the product will scan users’ iTunes libraries and then mirror them with Apple’s own high-quality audio files stored in the cloud.

Mac OS X Lion will bring iOS features “back to the Mac,” including home screens, tighter integration with the Mac App Store, new multi-touch gestures, and full-screen applications that auto-save and auto-resume. Also the Mac OS X Lion SDK will get a significant update, bringing it closer to the iOS SDK.

iOS 5 and Mac OS X Lion are both rumored to have deep integration with the new iCloud service.

iOS 5 is expected to offer improved voice commands, but the software is not expected to be shown running on a new iPhone 5.
The iPhone 5 is expected to show up sometime later this year, and not at WWDC.

Rumor has it that Apple also plans to add widgets to to iOS 5, Apple would also be planning to revamp its notification system, since the person that designed HP’s Palm webOS elegant notification system was hired by Apple.