OS X Mavericks to be Released this October
According to 9to5Mac, OS X Mavericks won't be released until October. Following most OS X releases, Apple launches it a day after their quarterly earning announcement. Their next quarterly announcement will be on October so that might be when OS X Mavericks will be released.
However, iOS 7 is still expected to be released alongside the iPhone 5S and 5C later this month. The media event will be on the 10th and the devices announced are rumored to launch the 20th.