I just added a skin for the XBMC; xTV 2.1 and the theme browser for it, in to the files section Xbox->Skins->XBMC.
Its a wonderful skin that has many neat futures inside (ex. DVD cover flow, Music cover flow.)
It allows you to download cover art off of IMDb for you DVD collection, and Album art for your music. It also has its own theme browser just like MC360. I recommend the download