About iOS 4.3 Software Update

This update contains new features and improvements, including the following:
Personal Hotspot*
Share iPhone 4 cellular data connection with up to 5 devices (combination of up to 3 Wi-Fi, 3 Bluetooth, and 1 USB)
iTunes Home Sharing
Play music, movies and TV shows from a shared iTunes library on a Mac or PC (requires iTunes 10.2)
New AirPlay features**
Play videos from the Photos app including the Camera Roll album, iTunes previews, enabled third-party apps and websites on Apple TV
Play slideshows from Photos on Apple TV using transitions available on Apple TV
Faster Safari performance with Apple Nitro JavaScript engine
HD video out using the Apple Digital AV Adapter***
View 720p HD videos from Videos app, iPod app, Photos, YouTube, Safari, Keynote, and enabled third-party apps on an HDMI display
Ping features
Push notifications for comments and follow requests
Post and Like songs directly from the Now Playing screen
Parental controls
New Settings
Messages setting for number of times to repeat an alert
iPad side switch setting to lock screen rotation or mute audio notifications and sound effects
Single tap conference call dialing with a pause to send a passcode
Bug fixes
*Requires iPhone 4 with tethering data plan
**Requires Apple TV (2nd generation) running software version 4.2 or later
***iPhone 4, iPad, iPod touch (4th generation)

For information on the security content of this update, please visit:
http://support.apple.com/kb/HT1222

This update is available via iTunes.

http://www.engadget.com/2011/03/09/apple-releases-ios-4-3/