http://itunes.apple.com/de/app/xcode/id497799835Neue Funktionen von Version 4.3.1
Xcode is now distributed as an application, rather than as an installer. This change enables Xcode to be updated directly from the Mac App Store.
• Includes SDKs for Mac OS X 10.7 Lion and iOS 5.1
• New code signing workflow supports signing OS X apps with Developer ID
• Adds installation of command-line tools to the Downloads preference pane
• Open Developer Tool menu launches Instruments, File Merge, and other tools
• ARC migration tool converts both retain/release and garbage collected code
• Additional bug fixes and stability improvements
