Admittedly part of the reason that being able to play media from your iPad via an Apple TV is that Apple decided not to put a hard drive in its most recent media player, so the only way it can access files is by streaming them, but the merit of that choice is a separate debate. If you're the kind of person who buys a lot of videos and music from iTunes, AirPlay provides a great way of getting that media to your TV or speakers (via AirPort Express). Plus, the futuristic feel of 'beaming' files around your house is just plain cool, and that counts for a lot.
The other changes and additions in iOS 4.2 are much more minor. Find my iPhone is now free, letting you send a message to a lost iPhone, iPod touch or iPad, as well as providing the option to remotely lock or wipe it, without needing a MobileMe subscription. We particularly welcome the option to change the font used by the Notes application; we find Helvetica much more aesthetically pleasing that the awful faux-realistic Marker Felt default.
More useful on a day to day basis are the Mail enhancements made available to the iPhone some months ago. Foremost of these are the universal inbox, and the ability to add more than one Exchange account at any one time. As we happen to use Google accounts for our personal email, as well as a 'normal' GMail account, this is particularly helpful - IMAP feels painfully backwards in comparison.
Also meeting with our approval is the addition of in-page searching to Safari. This is hidden as an option in the Google search, but there's not really a better place to put it and it is definitely useful. Our only criticism is that although you can skip forwards through instances of your search term on a page, you can't cycle back. By way of small consolation Apple has finally added an open-tab count to the new tab icon. Considering older windows are closed if you open too many new ones, it's particularly important to keep track of this, so it's amazing we've waited this long for a quick and easy visual cue.
A controversial change is the alteration of what was previously the iPad's orientation lock switch to a mute switch. Like the iPhone, the iPad now puts its screen rotation controls in the multi-tasking dock, along with its iPod controls. As the iPad has more space here, Apple has also added volume and brightness sliders here, which we like - we'd really love to see toggles for Wi-Fi and 3G too. That said, it was never hard to turn down the iPad's volume before and as we find ourselves locking and unlocking the screen orientation far more than we mute or unmute our iPads, we wish Apple had added a menu option to control what the hardware switch changes.
Such gripes are minor, though, and pale in comparison to the overwhelmingly positive impression left by iOS 4.2 in the iPad. With Christmas close to hand, and the competition finally getting their own tablets out, the latest update to Apple's tablet gives it a much needed shot in the arm. The criticisms we made of the iPad's hardware in our original review still stand, but the software is miles better not only addressing the failings of the iPad as launched, but adding in features such as AirPlay that we never thought we would want, but would now be loath to give up. If that's not the definition of a success we don't know what is.