According to iMore, Apple will begin taking US pre-orders for its next-generation iPhone on September 12th, the very same day the company is expected to unveil the product. That would represent a significant shift over recent years, where Apple has traditionally waited a few days following a hardware event (and surrounding media blitz) before letting customers reserve a handset. The gap has been closing, however: eager buyers needed to wait more than a week to pre-order the iPhone 4 in 2010, but could place orders for the iPhone 4S just three days after its debut last fall.
iMore's sources have also revealed October 5th as a likely target for the first phase of the new iPhone's international rollout. It's expected that customers in the US and select other regions will be able to buy the device starting September 21st, so such a timeframe doesn't strike us as unreasonable. Of course, as is usually the case with these rumors, all of this could easily change — particularly since Apple has yet to make its plans for a press event official. August is rapidly coming to a close, though, so we should know more in just a matter of weeks.