The world map works as a type of menu system from which you manage your missions, with various dungeons and towns you have access to accessible displayed between missions. (plusxp.com)
I was initially not a fan of the new menu system as I really enjoyed the previous model, but this version has grown on me. (stickskills.com)
However the main addition seems to be the new menu system for the 3DS home menu. (gamingreinvented.com)