The 2011 Worldwide Developers Conference filled up within just 12 hours, perhaps due to its rumored double-focus on "the future of iOS and Mac OS," as spoken by Apple senior vice president Phil Schiller in a press release early Monday morning. Earlier in the day, several Mac and iOS developers had joked about the conference selling out early on Twitter; by 4PM PST, the joke had become reality: the "Buy now" button featured so prominently on Apple's WWDC Website had been replaced with a graphic proclaiming the conference's "SOLD OUT" status.

While WWDC has been selling out before its opening day since 2008, this year's speedy turnaround is particularly unusual: Apple's conference last year in 2010 took eight days to fill to capacity, while it took a whole month for the 2009 event to sell out. As previous conferences have primarily focused on either Apple's mobile or desktop OS, but never both, it's likely the promised double-whammy of available tracks for both the Mac and iOS attracted a much larger pool of developers than last year's iOS-centric conference.

For those lucky enough to grab a ticket, WWDC 2011 will take place June 6 through June 10 and feature over 100 technical sessions for both iOS and the Mac OS on Application Frameworks; Graphics, Media, and Games; Developer Tools, Internet and Web; and Core OS, in addition to its signature keynote event.