Already in its seventh developer beta, iOS 5 is supposedly scheduled to reach golden master status—the official version which will be available to end users—during the last week of September. This latest tidbit comes from analyst Ming-Chi Kuo, who believes Apple will unveil what is essentially an updated iPhone 4 model in mid-October.

According to a research note supplied to MacRumors, Kuo said that Apple's contracted iPhone assemblers, Foxconn and Pegatron, are set to receive the final version of iOS 5 between September 23 and September 30. This version will supposedly be flashed on to existing iPhone 5 units that have already begun production, allowing for the devices to roll out around mid-October. The information aligns with some previous rumors that pegged the device to ship in the same time frame.

Also, according to Kuo, supply chain checks haven't revealed any evidence of a rumored new form factor. Instead, all evidence supports our belief that the next-gen iPhone will be largely the same as the current device with a few minor changes. The iPhone 5 will continue to use a 3.5" Retina display, and will likely retain the full glass front and back. Upgrades are expected to include an A5 processor with 512MB of RAM—the same as the current iPad 2—and an 8 megapixel rear-facing camera.

While analysts are often wrong in their prognostications, the firm date for the expected golden master release of iOS 5 has piqued our interest. While Apple only promised a "fall" release for iOS 5 in June, this seems to be the closest we have heard of a final release date, and it makes sense. Apple is currently releasing beta updates to Mac OS X 10.7.2, iTunes 10.5, iOS 5, and iCloud on a regular basis. All these pieces of software will have to be ready and vetted to launch iOS 5 and ostensibly an updated iPhone.

Apple has yet to send out invitations to the media for what had become an annual early September announcement of new iPod models. Such an event seems the most likely time to announce a new iPhone as well. However, it looks as though it won't happen until late September or even October this year—when iOS 5 is in final form and ready to show off to the public.