Published 15th July 2008
Today Wordpress 2.6 was released. In my opinion, the most useful addition is the revision system which uses an extended version of the PEAR Text_Diff package and enables a Trac-like view between post revisions.
Additionally the autosave function saves the content in its own revision every 60 seconds, even when a post was already published. This makes it possible to have a simple live/working revision system for published posts.
Prior to 2.6 the autosave function wasn't enabled when editing an already published post, meaning that you only had a live revision of your post, and needed to edit the content in an external editor to save a draft of it.
With Wordpress 2.6 you can now use the autosave feature to have a working revision of the post in your Wordpress backend. A notification shows you if there's a newer revision of the post available.