While there are no new features have been released in the latest version of WordPress (2.6.1), there are over 60 bug fixes which might just be worth the upgrade.
From the WordPress Blog: 2.6.1 offers several improvements for international users. Styling of the admin for right-to-left languages is much improved thanks to the efforts of the Farsi and Hebrew translation teams, and a mysterious gettext bug caused by certain PHP configurations is now fixed. For IIS users, 2.6.1 fixes several permalink problems. Image insertion problems in the Press This feature experienced by IE users are also fixed. Of note to everyone is a fix for a performance bug in the admin where those with a lot of plugins would experience slowness on some pages.
WordPress users can download the latest stable release here: http://wordpress.org/download/