According to strings found in the iOS 5 SDK, the next major release of Apple’s mobile operating system will be able to update over 3G networks. Apple unveiled iOS 5 at WWDC earlier this month, and highlighted OTA updates as one of the key features. OS updates are generally pretty large, but iOS 5 allows users to only download “delta” changes, or just the bits that have been modified from the previous version. We’re not sure just how small these updates will be (comments in the code suggest 500MB, but that could include unpacking and moving files around), but we’re sure carriers would be in a tizzy if they hogged significant amounts of bandwidth.
9to5 Mac notes that Apple may be limiting 3G over the air updates to smaller x.x.1 releases. These could be important and possibly time-sensitive security fixes, which would likely be very small.
iOS 5 will be released in the Fall (most likely September), and you can check our list of most of the major changes here.