To be noticed that WordPress 2.5.1 release. It includes security fix. So I recommend you to upgrade as soon as possible.
* 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
2.5.1 has over 70 fixes. Don’t waste your time and put your Blog under security shadow. Download it now and upgrade it.