Update 1: iOS 5 Final version has been released for Download and Jailbreak - Click Here
Apple has released the first software that can be downloaded using Apple's new over-the-air. The guys over Macrumors noted that iOS 5 beta 4 over-the-air update is 133 MB while the full version is 824 MB.
Over-the-air software update is downloading code that has changed only. Over-the-air update on iOS 5 beta 4 saves about 700 MB of downloading. Thanks Apple ;)