Our website developer, Casey, stays on top of client’s WordPress updgrades and administration. While a lot of WordPress upgrades prove to be updates to the security, WordPress 3.4’s upgrade is more important, for the following reasons:
  1. Embed your Tweets
  2. HTML in image captions now supporter
  3. Better performance
  4. Ability to choose header and background images from media library
  5. New header API lets you customize header sizes instead of being stuck with the size the theme developer set
  6. Improvements to the help system to make it easier to use your site
  7. Better support for mobile devices (finally!)

To learn more read the official release notes (http://codex.wordpress.org/Version_3.4)