With the release of the iPad mini Xcode has been updated to version 4.5.2 this update includes:-

Support for iPad mini and iPad with Retina display (4th generation).
Additional bug fixes and stability improvements.

Xcode 4.5 includes

• SDKs for OS X 10.8 Mountain Lion and iOS 6.
• Auto Layout now supported on both OS X and iOS.
• New localization workflow can share a single base .xib or .storyboard file for multiple locales.
• OpenGL debugger for iOS analyzes performance and suggests improvements.
• Debugger watchpoints can be set when running on a connected iOS device.
• Objective-C @synthesize command is generated by default when using properties.
• Objective-C adds literal syntax for numbers, arrays, dictionaries, and expressions.
• Xcode 4.5 runs on both OS X Lion and OS X Mountain Lion.
• Enhanced for the MacBook Pro with Retina display.

The latest monthly market share data is available from Net Applications and Mac OS X continues to show a steady rise now up to 7.16% (a rise of 0.3%). Adoption of Mac OS X 10.8 is now over 25% of the Mac OS X version share and steadily increasing.

In the mobile/tablet space iOS continues to dominate (63.48%) this represents just under 10% of the online presence with desktop/laptop still at 90%.

XQuartz was updated recently to version 2.5.3