Obviously, it's very premature to suggest that anyone knows when Apple will launch its next iPhone model, and certainly whether or not that model will actually be called an iPhone 6. Nevertheless, that won't stop the rumors and speculation from running amuck, just as they did with the iPhone 5 for the past year.
Last week, Ed Valdez at Technorati made the case that the device will launch by June 2013, citing six reasons. I won't run through them all here, but he does write, "Product managers/marketers use the S-curve to carefully manage when the next product should be introduced. Apple has been a master of maximizing revenues and profits from the launch of a product to the ramp phase (mass market adoption) to the mature phase (sales plateau, then subside). While the average iPhone PLC has been 14 months, the peak sales curve (ramp phase) of the iPhone 4S spanned a period of three months and the peak sales curve for iPhone 5 is projected to be 4 months. Thus, Apple needs shorter PLCs to continue to return value to its shareholders and deliver new value to consumers because revenue, profit and earnings shrink within two quarters after an iPhone announcement. No company wants lackluster sales for the vast majority of a product life cycle."
He also says, "The iPad 4 announcement tipped Apple’s hand by showing us what’s possible: a shorter time to market (TTM). The iPad 4 launch cut five months from the average iPad TTM and the iPhone 5 launch cut three months from the average iPhone TTM. Even if Apple were to announce iPhone 6 by June and make it available in July, that would be 10 months TTM from the iPhone 5 which is quite doable because the iPhone 5 had a TTM of 11 months. I’m forecasting June 2013 only because it synchronizes well with their next anticipated WWDC in June of next year. The quick TTM for the iPad 4 will translate to a fast TTM for the next iPhone."
NetworkWorld thought enough of Valdez's predictions to discuss them, but also says that "None of these claims are very convincing."
If iPhone 6 speculation isn't enough for you, there are already iPad Mini 2 rumors coming out too. Get ready for a lot of this stuff again over the coming months.