Fans have been kinda keeping their fingers crossed for a September release of OS X Mavericks ever since Apple at June's WWDC formally announced the new version of the desktop operating system for Macs. The guiding logic was that the company would need to release both iOS 7 and OS X Mavericks simultaneously because the two releases complement each another. For example, Mavericks with its native Maps app lets you create a route and send it wirelessly to your iPhone for navigation.
Or, reading a notification on your iOS device now automatically clears it on your Mac and all of the other devices. However, a reliable blogger now quotes sources with knowledge of the launch plans as claiming that OS X 10.9 Mavericks is due at the end of October so Apple could "focus the majority of its software engineering resources on pushing out iOS 7 alongside the new iPhone hardware over the next couple of weeks"...