Apple has just released iOS 4.3 beta to developers.

New features include: Developer access to AirPlay API, Four and Five-finger gestures, and the return of the hardware orientation lock for iPad, a feature that upset many when Apple suddenly removed this feature with no software option to re-enable it.

Also interesting to note is the lack of mention of the Mobile Hotspot feature rumored to be included in 4.3 for all iOS devices by the Verizon announcement yesterday.

http://www.macworld.com/article/157114/2011/01/ios_4_3.html

http://www.macstories.net/ipad/apple-brings-hardware-rotation-lock-back-in-ios-4-3-for-ipad/

http://www.businessinsider.com/huge-verizon-iphone-will-act-as-a-mobile-hotspot-2011-1