Twitter for iPhone 4.3 is coming and the release notes are already available, as 9to5Mac noted on a tip. The redesigned App Store on iOS 6 has a section that shows the update history and on Twitter for iPhone's update history you can now find the release notes for the next version.
The release notes show that the app will go under significant changes:
- Discover more interactive experiences inside any Tweet: when you view tweet details containing links to partner websites, you can now see content previews, view images, play videos and more.
- Special experience around selected events: we'll curate accounts and surface the best Tweets and photos form those involved
- Improvements to autocomplete suggestions when you search for people in Connect
- Push Notifications for Tweets: you can know immediately when selected people you follow have tweeted
- Ambient notifications: enables you to see brief non-interruptive notifications in the status bar while you are using the app
- Discover: now indicates when new stories are available for the user to load
- Trends: support for personalized trends
- Tappable avatars that take you directly to user profiles
- Performance improvements
- Support for password entry in app when experiencing authentication issues
- Hungarian language support
- Updated with new Twitter bird
- Many other tweaks, polish, and bug and crasher fixes
These changes included in 4.3 take some notes from apps such as Tweetbot with the ambient notifications and it also adds new Twitter features available via website.
No way to know when it will be available. The leak is likely to be an iOS 6 bug.