In an interview with Jon Erlichman from Bloomberg West, Apple analyst from Piper Jaffray, Gene Munster claims that he thinks that not only will the next generation of the iPhone come in October. He puts the reason why he thinks that it will be coming out that late in the year down to the fact that Qualcomm's 28nm chips are short in supply and because the iPhone 5 is likely to be LTE capable it would mean either a late Q4 release or the usage of a different chip which in Munster's opinion is unlikely because of Apple's relationship with Qualcomm.
Ubergizmo, Gene Munster: iPhone 5 May Release in October [Rumor]