Today Twitter for iPhone 4.3 was released on the App Store, a major update to the official Twitter client that brings with it the ability to view enhanced and expended tweets right in the app. Here's a rundown of the features:

• Expanded Tweets -- when you view Tweet details containing links to partner websites, you can now see content previews, view images, play videos, and more (rolling out gradually)
• Enhanced experience around selected events with the bets Tweets and photos from those involved
• Push notifications for Tweets -- choose to receive notifications from people you follow any time they tweet or retweet
• Ambient notifications -- enables you to see brief non-interruptive notifications in the status bar while you're using the app
• Improvements to search autocomplete for users
• Discover -- now indicates when new stories are available for you to view
• Tappable avatars take you directly to user profiles
• Performance improvements
• Support for password entry in app when experiencing authentication issues
• Support for the Hungarian language
• Icon (image at right) features the new Twitter bird!

You can download the new Twitter for iPhone and iPad now, completely free.