Sources close to BGR claim that Apple will release iOS 5 in early October. If those sources are correct we could be installing iOS 5 within 2 to 3 weeks on our iDevices.
The reported release schedule for the next few weeks will see iOS 5 beta 8 released on Friday, Sept 16th, followed by the GM (gold master) release on the 23rd of September.
A Golden Master is essentially the final release before going live. The GM release should see the final release of iOS 5 released a week to two weeks later.
Meanwhile, according to Apple Insider, Apple informed their customer support teams to expect an influx of iOS 5 related calls on the 10th of October.
It is also widely expected that the iPhone 5 will be released in mid October.