If the rumor mill is to be believed, Apple will announce their new iPhone on Sept. 10th. That is not too far away, and as such means developers are working hard to have launch titles available. Realistically, I doubt that Apple will make the iPhone 5s/c or whatever it will be called, ready on the day of announcement; however, I do believe that they will make iOS7 available almost immediately.
As a developer, I am looking forward to releasing updates of my app that will more closely align to Apple’s new UI vision. I am also looking forward to all the new API’s that Apple has been talking about since June’s WWDC.