For those users who want to try their hand at skinning the textures on the LOTRO UI, we have released a "UI skinning art pack". This zip file contains all of the art asset tgas and a SkinDefinition.xml file to help you get started.
You can download the file from here (scroll to the bottom of the page, under the "UI Customization Toolkit"):
http://www.lotro.com/index.php?page_id=98&siid=25
For information on skinning the UI (where to download and install, how to modify the file) see this page:
http://lotro.turbine.com/article/330
-P