Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
Apple Issues Invitations for Media Event on September 12
Apple is of course expected to introduce the next-generation iPhone and give a final preview of iOS 6 at the event. Apple's "iPad mini" is reportedly also nearing a launch, but sources have indicated that Apple is planning a second media event for October to introduce that product. Apple's iPod lineup is also rumored to be seeing an update at one of the two events, while rumored iMac updates and the launch of a 13-inch Retina MacBook Pro are likely to appear separately.
There's clearly a "5" in the shadow of the invitation, suggesting that Apple's next iPhone will indeed be called the iPhone 5.