According to AppleInsider, certain sections of the AppleCare division have told employees to prepare for a heavy influx of calls relating to the new iOS 5 during that time period. From October 10th through the 12th, Twitter is expecting to have a developer event related to iOS 5 which would suggest that the software would be made public before then. In the past, Apple has introduced a new OS prior to an iPhone launch. For example, last year Apple brought out iOS 4 on June 21st and 3 days later launched the Apple iPhone 4. A year before that, iPhone software 3.0 was brought public on June 17th with the Apple iPhone 3GS made available on June 21st.
This year might not be any different. If the October 9-12th blackout dates have to do with iOS 5, surely the October 14th-15th dates must deal with the launch of the 5th-generation Apple iPhone, whatever it is named. With speculation that the next iPhone will be introduced during Apple's October 4th event, the timing would seem to be in line to expect its launch 10-11 days later.