There are a few custom themes that do not use moviesheets[think Tinwarble and firetix] and plus the original themes.
I know there is one out there to generate .xmls instead of using built in Hub options… one by one.
here is another tool that get is getting some serious updates
v1.0.7 released: WDTVHubGen - Looks up Movies, TV Shows and creates XML for the Hu6
NoSlack913 has been working really hard, working with other users to fix bugs and make it a good product. So anyone using these themes might want to check out this application.