Some days ago their was a rumour going around that iPhone 5 may not launch this year because of some problem in the supply of its part and because of this it would launch in 2012.But according to a Korean site ETNews.co.kr Apple will launch iPhone 5 this year and according to them they would launch it in the last week of June this year.
But looking at the previous rumours Apple had no plans to launch it in WWDC , may be they would launch it in different event.Whatever the case is I think Apple would not break the yearly launch of iPhone.As this Korean site has mentioned.
iPhone 5, the next model of iPhone 4, will be released on the coming 4th week of June. In the midst of the iPhone 5 postponement rumors, Apple has confirmed that iPhone 5 will be released as planned and it will be released simultaneously in Korea through SK Telecom and KT.