Apple has just released iOS 4.3 for iPhone, iPad, iPod touch and Apple TV. You can now check your iTunes to download and update your iOS if you want to. This new version is now available with AirPlay support for third-party apps.
Apple had made iOS 4.3 Beta for developers earlier before. Read Apple brings out iOS 4.3 beta to developers for iPad, iPhone & iPod Touch.
This new version is available for iPhone 4, iPhone 3GS, iPad, Apple TV, 3rd and 4th generation iPod touch. But the earlier iPhone, iPods cannot be updated with the new OS.