There are plenty of new spell and feat effects, as the total number of feats and spells has been approximately doubled.  Plenty of old favorites return, but most people are eager to hear about dual-wielding of weapons.  In the original game, you could unlock a game mode called The Gauntlet, in which you played Drizzt, a dual-wielding Dark-Elven ranger.  Unfortunately, only by using Drizzt could you unlock the dual-wielding skill.  Now, you’ll be able to use a weapon in each hand from the very beginning of the game.