From Ars Technica:
New APIs in iOS 4.3 will allow developers to extend AirPlay support to their own apps.
Forget the ‘hotspot’ hooplah — this is the best new feature to come from the new 4.3 iOS beta. I’ve been wondering about this ever since AirPlay was first announced, and no one seems to have had a straight answer about the AirPlay API’s existence. Now we do, and it’s going to be amazing.
There’s also room for a convincing argument over criticism toward the Apple TV’s lack of ‘apps’. Doesn’t this API bridge most of the gap? What exactly do you want on the Apple TV?
MLB At Bat? Hulu? Pandora? Last.fm?
Streaming audio (from Pandora, for instance) already works on Apple TV through your iPhone/iPod/iPad. Video doesn’t, but will once 4.3 releases. You have an optimal remote control (the aforementioned deviced) and a user interface you’re familiar with (the app to which you’ve already grown accustomed). Is it necessary for developers to redesign that app for yet another interface at yet another resolution? Why not just piggy-back off the apps for iOS? It’s a simple use of technologies already supported without the requirement of having to design something as atrocious as the Google TV’s remote to control a new UI paradigm.
If it’s back and forth interaction (something not currently supported — such as for gaming), then we’ll have to look elsewhere. But you can’t simply enable that kind of technology in the current Apple TV without the use of a new, bundled remote control. The AirPlay-enabled apps via iOS devices work because they aren’t intrinsic to the Apple TV — they’re accessories. But apps on the Apple TV would be intrinsic, and would therefore require an entire redesign of the product.
4.3’s third-party AirPlay is the right direction. If you want to game on your TV, there’s a way to do it — see Big Bucket Software’s use of the iPad, iPhone/iPod, and a VGA cable.