I was thinking why not create a HTML/css/javaxml type skin viewer and so i did. This was put together in about an hour so it's probably screwy but I'd love to get some feedback on it. All the positioning isn't put in yet but I think you'll get the idea when you look at the code. What you would do is just:
1. Drop "lotro_skin.html" in your skin's directory along with "defaultBackground.jpg" (thanks D.Hicks!!).
2. Create all your elements as PNG's first but list them as TGA's in the skin definition file like normal.
3. Once your done just batch convert them all to TGA's.
I'll continue to work on all the CSS positioning and upload a new version later. I tested it with Firefox so I'm sure it doesn't work in IE.