iOS 5 which as we know, is the most advanced software update for iOS Devices ( iPad, iPhone, iPod Touch ) so far. However it will not be released by Apple until this fall. Apple developers on the other hand can download it today. And as rumour has it, Apple's latest software update will not allow downgrading to previous versions of iOS. Now our best guess is that this is Apple's attempt to prevent Jailbreaking and if a Jailbreak isn't released for iOS 5, this may result in us having to choose between Jailbreaking and iOS 5.