Lots of ChangesFollow

There's still a poison questline, but you no longer need to do it. You can automatically purchase pre-made poisons starting at level 20 now, but you can still do the quest chain just for the hell of it. Instead of learning new poisons as you go along you simply gain the ability to purchase and use more powerful versions as you level up.

Also, lockpicking is your level*5 if I recall and nothing's changed about that, any old list should still be accurate unless it doesn't include Northrend areas.