When I first learned about iPad's feature set, my primary disappointment was that it could not be pitched to users as a stand-alone computer replacement. In other words, its addressable market was limited to users who'd already bought another computer with which it was possible to sync content and download software updates. It appeared iPad might be doomed to be tethered to some other "real" computer.
With Apple's announcement of iOS 5, Apple enables data sync without a main computer – wirelessly to iCloud – even to the extent of updating the system software. iPad is now a serious contender for a front-line machine for users whose demands are within the realm of iPad. Given what iPad's app developers are doing – and what Apple is doing with iPad development – the scope of those demands will quickly reach quite a few users.
Growing the size of Apple's addressable market for the iPad by freeing it from cable-based sync is a huge boost for the long-term prospects of iPad.