The iOS 4.2 update introduced AirPlay support on iOS devices, but the feature was then only available to some of Apple's built-in apps, such as Safari and YouTube. In iOS 4.3, developers will be able to harness AirPlay in their own apps, extending the potential of the feature. The pre-release version of the Apple TV software will allow developers to test streaming to Apple's little black box.

Another feature of iOS 4.3 is a set of new multitouch gestures that could significantly enhance interactions on the iPad. While the tablet is capable of accepting input from more than two fingers at a time, Apple's official set of multitouch gestures has so far only employed two fingers for things like pinch-to-zoom on a Web page or twisting to rotate images in the Photos app.

In iOS 4.3, the iPad can use four- and five-finger gestures (and only the iPad appears to get these features, at least in this release). Apple even details specific examples for developers to test, such as pinching out of an app to the Home Screen, swiping up to reveal the multitasking bar (which in iOS 4.2 is only accessible by double-tapping the Home button), and swiping left and right between apps.

And, to the delight of , iOS 4.3 appears to add an option for returning the hardware orientation lock that disappeared in iOS 4.2. show a preference that allows users to choose whether to use the switch on the side of the iPad for hardware orientation or the current function, muting.

Also included in this beta is full-screen iAd banners on the iPad and HTTP Live Streaming Statistics for tracking how viewers interact with streaming content. Notably missing, however, is any mention in Apple's documentation of the mobile hotspot feature that Verizon showed off on its version of the iPhone (we explained this feature in our ). The OS running on Verizon's device was version 4.2.5, and a rumor quickly began circulating that all iPhones would get the feature in iOS 4.3. But as far as we can tell, it isn't in this release.