Apple is expected to release the iPhone 5 in September along with the release of iOS 5. A new report by Digitimes suggest that Apple has started to lower orders for components needed for the iPhone 4. This would mean Apple is getting ready to wind down production of the iPhone 4 and switch over production capacity to the iPhone 5 soon.
The Taiwanese PCB (Printed Circuit Board) makers are the source for this information. Industry sources say that the orders from Apple are down by 10%. As the slow down is not that dramatic, I assume that Apple is not yet starting production of the iPhone 5. Apple might go into mass production around early August to produce the first inventory of the iPhone 5 for a September launch.