Well, for one thing, the cards aren't shaped like coffins and doors and such anymore. =P
The combat mechanic has been changed to be card-based, to the general displeasure of most it would seem (I'm fairly ambivalent myself. I'll try the card-based system a few times, although I figure there's a good chance I'll end up looking into a dice based variant if only so I can make homebrew versions of all the other heroes in Terrinoth without needing to make a set of homebrew power cards for each.)
There's a new "sun track" that imposes a time limit on the game, although it seems like it's plenty long enough that you'd probably be dead in the old edition if you stuck around the dungeon that long anyway.
Monsters have tokens that hang around if they aren't killed. It's been a while since I played the older version, but I don't recall that being the case before.
Other than that it's fairly similar to what I remember. Still as deadly as ever, anyway, and that's the part I like about it. =)