– Performance improvements for the Dashboard, Write Post, and Edit Comments pages.
– Better performance for those who have many categories
– Media Uploader fixes
– An upgrade to TinyMCE 3.0.7
– Widget Administration fixes
– Various usability improvements
– Layout fixes for IE
For those who are having problems with the media uploader issues in IE6 and IE7, they are now all fixed in WordPress 2.5.1. Get the latest version here.