Mavericks won't be far behind but yeah I think iOS 7 will be first with the release of the next gen iPhone. Then there will be a slew of Mac releases and I'm thinking they'll announce a formal release date for Mavericks. Perhaps at a Mac Pro Apple Event? Or, maybe just an Apple Event in general with updates to lots of Macs, including the Mac Pro (being the major announcement at the event).
8/21/13 at 8:07pm