iOS 4.3 was announced on March 2nd, when Apple announced the launch of the iPad 2. Both the new device and the operating system were supposed to become available on Friday, March 11. Apple went ahead and let device-owners get iOS 4.3 a little early instead. The operating system can now be downloaded.

“With more than 160 million iOS devices worldwide, including over 100 million iPhones, the growth of the iOS platform has been unprecedented,” said Applce CEO Steve Jobs upon the announcement. “iOS 4.3 adds even more features to the world’s most advanced mobile operating system, across three blockbuster devices—iPad, iPhone and iPod touch—providing an ecosystem that offers customers an incredibly rich experience and developers unlimited opportunities.”

New features of iOS 4.3 include faster Safari mobile browsing performance with the Nitro JavaScript engine, iTunes Home Sharing, enhancements to AirPlay, the choice of using the iPad side switch to either lock the screen rotation or mute the audio, and a Personal Hotspot feature for sharing an iPhone 4  data connection over Wi-Fi.

iOS 4.3 is compatible with the iPad, iPad 2, iPhone 3GS, iPhone 4 (GSM model), and the third and fourth generation iPod touch.

The iPad 2 is still scheduled for release on Friday. If you already have the first generation iPad, you can get a hundred dollar discount. If you don’t have an Apple Store near you, Best Buy stores will have them at 5pm.