From Apple PR this morning:
Apple® CEO Steve Jobs and a team of Apple executives will kick off the company’s annual Worldwide Developers Conference (WWDC) with a keynote address on Monday, June 6 at 10:00 a.m. At the keynote, Apple will unveil its next generation software - Lion, the eighth major release of Mac OS® X; iOS 5, the next version of Apple’s advanced mobile operating system which powers the iPad®, iPhone® and iPod touch®; and iCloud®, Apple’s upcoming cloud services offering.
It don't see how Apple could spell it out any more, but this year WWDC is all about software. Any next-gen iPhone hopefuls will have to wait until September, likely.
I'm glad to see Mr. Jobs will be on stage again. This medical leave has been very different than his previous ones. He is still very much involved during his absence.
Lastly, the iCloud rumor seems true. I can't remember the last time (if ever?) Apple pre-announced a product via press release. Needless to say, I have a feeling it will be big.
And who knows, maybe there will be "One More Thing".