As you know that Apple used to push its iOS updates throw iTunes, then you have to connect your iOS device to PC via USB to apply the new iOS update. So that Apple will bring over-the-air service.
Starting from iOS 5 Apple will start to introduce over-the-air software updates service. Precisely, when new iOS update to your iPhone, iPad or iPod touch is available, you will get an update notification and then you can update the software right on your iOS device. Actually, Apple’s competitors is already introducing over-the-air service long time ago.
Multiple sources (one as far back as March) say the new feature will debut in iOS 5, meaning iOS 5 will not come over-the-air but following point updates to it will. Just like tethering in iOS 3, Apple has the technology but cannot just unleash it everywhere. Apple and Verizon Wireless are said to have been in talks over these wireless software updates since early this year. Sources could not comment on whether or not Apple is negotiating similar deals with AT&T or international iPhone carriers.
It makes sense that Apple would have to make small update sizes which may be via incremental patches rather than full iOS downloads. I hope to see this as soon as possible 😉