I concur, John Howe's art work is just phenomenal. Just the thing to inspire DMs.
First few things that popped into mind that would be on my wish list:
-As accurate a description as you can have of the Middle-Earth. By this I mean that you won't be a wizard or such because there just weren't casters around, no flashy light-effects etc, and the game isn't balanced - if your ancestors were from Numenor or you are a Grey Elf, you probably are better than a hobbit or any other man from pretty much anywhere.
-It would be at least a tiny bit more forgiving if you try to play narratively than MERP was (I know this could kind of clash with my first point, but luckily I'm not a designer). My friend has told me countless times of the instance he played a hobbit adventurer:
HIM: I climb atop the roof to see the area better.
*DM rolls*
DM: You fall and die.
HIM: Oh. Well, that was fun...