It seems Apple's next iPhone-related launch may come exactly 3 years after the debut (rather than announcement) of the first-gen model, as the dates for Apple's next Worldwide Developer Conference are thought to have been revealed.

AppleInsider has it that a calendar listing for San Francisco's Moscone Center (the venue for the event in the past) details a "Corporate Event" from 28 June 2010 to 2 July 2010. Previous Apple events have been reserved under the same phrasing.

Earlier this year WWDC 2009 took place from 8 June and saw the introduction of the iPhone 3GS. It's thought 2010's event, 3 years after AT&T was named as the exclusive operator for the iPhone in the US, could see Apple announce further carriers for the phone, as it has here in the UK.