Update: Apple now says 3-hour keynote listing an error
Jobs' keynote will in fact run the traditional 90 minutes from 9:00 AM till 10:30 AM on June 11th, not 9:00 AM till 12:00 PM as original reported by Apple's WWDC website.
Apple has now updated its website to reflect the change and confirmed in an e-mail to Gizmodo that the earlier posting was indeed a somewhat elaborate typo.