Kodawarisan, a Japanese web site, is reporting that Apple's Fall Event, which previously focused on iPods but will likely include the iPhone 5 announcement this year, is scheduled for Wednesday Sepetember 7th, 2011. The rumored date jives well with previous years.
Apple has always targeted early September for their Fall Events. Last year, the Fall Event was held on September 1st. In 2009 and 2008, it was held on September 9th. So it does make sense from a historical perspective. This year is a little different though because it will be the 10th anniversary of the 9/11 attacks on September 11th; it seems unlikely, perhaps, that Apple would want to compete with such an emotional and all-encompassing event for the type of media attention their product launches usually command.
Update: MacRumors says sources are now completely denying that an event is planned for September 7th. We'll have to sit tight and see for ourselves.