Mark Gurman, writing for 9to5Mac:
For the launch of both OS X Lion and OS X Mountain Lion, Apple released the new operating systems the day following an earning results release. Apple traditionally shares its Q4 earnings numbers during the second half of October, so perhaps Apple will release Mavericks the day following its Q4 results announcement.AllThingsD corroborated the report with its own sources.
“AllThingsD has confirmed that OS X 10.9 will not launch this month, but next,” author John Paczkowski claims. “Sources say Mavericks will arrive at market sometime in late October, well after the release of iOS 7″.While primarily focused on optimizing performance and battery life on notebooks, Mavericks brings a few notable user-facing features such as Finder Tabs and Tags, standalone Maps and iBooks app, various Safari enhancements, improved support for multiple displays and richer notifications.