Below we've outlined what's new in iOS 4.3.
Apple's media-sharing AirPlay already allows you to share your music, photos and movies by wirelessly streaming them from your iPhone, iPod Touch or iPad to your HDTV. But now the application is getting a much needed feature: the ability to stream videos from your Photos app. So, now you can shoot video with your device and then easily show it off on your HDTV.
Safari Performance Increase
iTunes Home Sharing Enhancements
You can now share content between your iPhone, iPod Touch, iPad, Mac or PC using Wi-Fi. You can wirelessly stream your music, movies, TV shows, podcasts and whatever else you like from one device to another. For instance, if you've got music in your iTunes collection that you haven't synced yet, you can still listen to it using your iPod, iPod Touch or iPad by streaming it wirelessly from your desktop to the device of your choice.
iPad Side Switch
This one's exclusively for iPad, but still interesting. You can now customize the small switch on the side of your iPad to either lock the screen rotation to either horizontal or vertical, or toggle between muting the volume and turning it back on.
Personal Hotspot for iPhone 4
You can use your iPhone 4's 3G connection to create a Wi-Fi hotspot for other wireless devices you own. By enabling this feature, you create a hotspot to connect to with your laptop, iPad or any other device using Wi-Fi, Bluetooth or USB. You're able to share your iPhone 4's 3G connection with up to five other devices or three devices using Wi-Fi. And all connections are password-protected. The catch? You'll have to pay for AT&T's DataPro 4GB/$45 tethering data plan to use the feature. (Verizon's iPhone already has this feature.)
iOS 4.3 is supported by iPhone 3GS, iPhone 4 GSM Model, iPod Touch (3rd gen, 4th gen), iPad and iPad 2. To download the iOS update, sync your iOS device, then click the Check for Updates button in iTunes.