Preview at WWDC likely in June, followed by September launch.
iPhone 5 Due for Release in September-October Timeframe?
According to Asian reliable source, next iPhone will be released in September or October , and this cycle seems to be kept for years.MacRumors has similarly heard from a representative of a supplier known to provide parts for the iPhone that Apple's ordering plans are pointing toward a launch of new hardware in the September.
A third source also claimed to iMore last week that Apple is targeting an October launch for an LTE-enabled iPhone 5, with that source also apparently having accurately named March 7 as the date of Apple's iPad 3 media event. Apple has yet to officially announce that iPad 3 event, but the date has been confirmed as accurate by the well-connected Jim Dalrymple at The Loop.
The claims of a September or October launch for the iPhone 5 directly contradict several previous rumors that had claimed Apple would be releasing the iPhone this summer, presumably at its Worldwide Developers Conference in San Francisco. That event that may be held during the week of June 11-15 this year, meaning that a product launch in the weeks after such an introduction would result in a very short lifecycle of only eight months for the iPhone 4S. Consequently, many have believed that Apple will indeed hold off on the iPhone 5 launch until later in the year as it did in 2011.