I'm excited for the story but I'm hoping there's more to the DLC than just that. Tougher enemies scattered around and stronger gear too hopefully.
There's definitely new enemy types from what I've read, and some kind of new rune system that gives you extra perks. I am kinda curious how it handles enemy scaling though. They've said it's meant for players around level 30, which is roughly the level you are when you finish the game, but the cap is technically much higher than that.
Remember though that if you've started NG+ the level requirement doubles so you'd have to be at 60.