Apple could have accidentally released an iOS5 feature several days before the WWDC conference. As proven by MacRumors, asking iTunes to check your app library for updates, the update page leaves a hint at a future feature, which the user who captured the information managed to screen-capture. The sentence underlined above relates to a feature currently non-existent in iOS, and means it may release as part of iOS5. If such a change was to happen it would mean that users could avoid manually re-downloading the app from the App Store, or syncing their Apple device with iTunes. Furthermore, it suggests an "Automatic Download" setting appearing for more than just apps. Apple have been rumored to be looking into over-the-air updates for some time now, and it seems plausible that this will be the case.
Over-the-air updates are typically among the less well supported methods of releasing new updates for software, as some network providers choose to not support them for various reasons. It is common for network providers to contact customers using a specific handset via an SMS in order to alert them to the existence of newer software, and is typically done in a manner to prevent service disruption for other users. Should Apple implement the feature, it is not yet clear what network providers will work with the system and what will not. Over-the-air updates are occasionally pushed for Android devices, though have been unusually absent from Apples products since their release. Assuming the system is implemented for all devices running iOS it could appear available with both the iPod Touch and the iPhone, as well as the iPad. Rumors have suggested that the iPhone 3GS and other older models will not be able to run iOS5. The new update system may have made this possibility more likely.