Announced yesterday morning, Apple’s 2011 Worldwide Developers Conference has sold out in less than 12 hours, marking a new record for quickest sell out. DigitalArts reports that the conference was sold out by 4:00 p.m. Pacific Time; last year’s conference sold out in eight days, which was then a new record. A search of eBay currently returns two results for tickets, one of which carries a Buy It Now price of $3,150, while the second has…