WordPress 3.4 released

codex.wordpress.org/Version_3.4

The Highlights:

Enhanced theme control

• Customize theme options before activating a new theme using Theme Customizer
• Use Theme Previewer to customize current theme without changing the front-end design

Custom Headers

• Improved Custom Headers with flexible sizes
• Selecting Custom Header Images and Custom Background Images from Media Library Screen

Media improvements

• Support HTML in image captions

Under the Hood improvements

• Improvements in WordPress internationalization and localization (more info)
• Different split in translation POT files for faster translations
• Codex XML-RPC information update accessed via XML-RPC_WordPress_API
• WP_Query improvements