A day ahead of the iPad 2 launch, Apple today released the latest iteration of its iOS platform, iOS 4.3. The new update brings a variety of new features to the iPhone, including new functionality related to Apple’s Airplay technology.

According to a press release, iOS 4.3 adds Personal Hotspot functionality for up to five devices (combination of up to three Wi-Fi, three Bluetooth and one USB). Users can also play music, movies and TV shows from a shared iTunes library on a Mac or PC (requires iTunes 10.2)

The new update further integrates communication between iPhones and Apple TV.

Users can now play videos from the photo app, including the native camera roll album, iTunes previews, enabled third-party apps and websites on Apple TV.

Other features include faster Safari performance, HD video out using the Apple Digital AV Adapter, Ping features, push notifications for comments and follow requests, post and ‘like’ songs directly from the Now Playing screen and parental controls.

iOS 4.3 will be available to iPad, iPhone and iPod touch users as a free software update. The update is compatible with iPad, iPad 2, iPhone 3GS, iPhone 4 (GSM model), plus third- and fourth-generation iPod touch.

Apple will launch the iPad 2 tomorrow at 5 p.m. local time at all 236 Apple retail stores in the United States and through the Apple Store beginning at 1 a.m. Pacific time. iPad 2 also will be available beginning at 5 p.m. local time at AT&T, Best Buy, Target, Verizon Wireless, Walmart and select Apple authorized resellers.