What I think most of us would trully appreciate in our interface is:

• Display order for Favourite Menu
  The Favorite items menu turns a pain when you don't always use hotkeys, as you have to search the item list by names. I would suggest an option in wich we decide what item/magic goes first and after, so the most used items get in the top of the list and the less used at the bottom.
  
  
• More categories for inventory
  The Misc and apparel category keeps way too much kinds of items. I would suggest new types: Jewelry, Quest items, Smithing items, Enchanting items, Useless items (things u can't equip or craft or anything)
  
  
• Use of the entire screen
  The 3d display window may be cute, but it is not worth half the screen. I'd rather see it smaller and use all that space to give more info in the list of items rather than just one item at the same time
  
  
• More options to order items besides alphabetically
  I miss oblivion's display orders for weapon damage, armor rating, value, weight. Alphabet is overrated!
  
  
• More info per item than just the name
  I can't compare items if I can just see the info in just one of them. It would be incredibly usefull if we see all the stats for all the items at once.

If someone is really into this, I can make a image for design references, as I am good at that, but haven't touch the modding.