When I have finished adding a GUI lib there will be a job for someone to create a Glest style skin.
This means learning the skinning system, creating xml files and images for widgets, mouse icons, fonts, etc.
Don't get caught up on the specific system at the moment. What we need is designs for: button, check box, drop down box, scroll bars, mouse icons, window, status bar. There are probably more but that will do for now.