iCloud is the glue that holds the new Apple experience together. It’s not too great a stretch to say that iOS 5 – along with OS X Lion – has welcomed in the next generation of Apple’s content ecosystem. Steve Jobs talked of Post-PC, and with its shifted focus from desktop to cloud, iOS 5 effectively downgrades your computer from essential to merely optional.
A huge and detailed review of iOS5 on Slashgear by Vincent Nguyen.
Update: Another review from AllthingsD here!