updated 04:40 pm EST, Wed January 12, 2011
Apple TV update supports third-party AirPlay
(Updated with more iOS 4.3 details) Apple has seeded two important iOS updates to developers. One is the first public beta of iOS 4.3, build 8F51448b. Several different downloads are available through the iOS Dev Center, oriented at the different devices. Apple has also published a new beta of the Apple TV firmware, allowing testing of AirPlay in web and/or third-party apps.
The exact contents of iOS 4.3 are unknown. Beyond extending AirPlay support, however, it should enable personal hotspots on supporting carriers, the first of which will be Verizon. In the past v4.3 has also been associated with the possibility of in-app subscriptions, which could break iPad magazines out of the requirement of paying for issues one at a time or through a web or paper subscription.
Update: The iOS 4.3 beta also reportedly enables full-screen iAd banners, and a series of new iPad-only gestures. Using four or five fingers, people can pinch to go to the homescreen, swipe up to show the task switcher, or swipe left or right to switch apps directly. The iPhone 3G and second-generation iPod touch appear to be missing from Dev Center downloads, which suggests that v4.2.1 could be the last version of iOS compatible with the devices.