Opened the game, and positive thing (might been an old patch, not played since release) is that they added 3 save games. So you can start a new game on hard mode and still have your old save. Also lets you import your current character into a save (without NG+) where you carry over your character with what I think are items/levels/skills, but game is reset and start from the beginning.
I just started a completely new character on hard. From what I've read they add 13ish? new dungeon type places to the base game, but other than that, it is mainly the same. The new item and loot system (which some reviewers like, some dislike) first start at the DLC zone.
It does run a lot smoother than it used to that's for sure.