Really neat! I noticed the 'hover' thing yesterday too ^^ Love these new additions.
Another thing I think would be really cool for lists, is if we could sort of custom group items in the lists. For instance, I have a Madoka Magica list. It would be neat if I could specify certain items to it's own line, with a title above it.
    
  
Hope my explanation is good. I could make an image example too. The list is my personal favorite feature on the site that you've made, it's really nice for managing collection and having some fun with it online.