To me, Dark Souls isn't "hard" necessarily, it's challenging. The great thing about it is that it mixes "grinding" from JRPG's and skill/reflex-based combat of action games perfectly. When you go grind through an area of enemies, you learn how to fight them more efficiently and you learn the nooks and crannies of the area, plus the game gives you souls for doing that, so you improve your character's stats by learning how to fight with skill. Thus, every time you go through an area, it's slightly easier.
I think the combat difficulty is fantastic in Dark Souls, and I hope that type of gameplay remains in Dark Souls 2. However, what the game needs to be is more accessible. My biggest gripe about the game is it's utter lack of explanation of just about anything. Unless you extensively read a wiki, you can play the game for 50 hours and not know how covenants, humanity, kindling, invasion works. I think for Dark Souls 2 ,there should be the standard game mode that will keep it exactly as difficult as DS1, but there should also be an option to give you an in-game wiki/journal type thing to explain the game's systems, give info on enemies etc. Also I think some kind of combat training mode or something would be cool, where you could learn how to fight different types of enemies with different weapons and abilities, just for practice.