I never thought he was anything special.
I heard they were gonna put him in the Animated Series, but the makers thought he was too shallow and violent.
I agree. He's Batman's equivalent of Carnage from Spider-Man. Very two dimensional, especially when comparred to the greatness of the likes of Joker, Two-Face, Scarecrow, Freeze etc.
His small role in Begins is polite and totally justified. I wouldn't have wanted to have seen any more from Mr. Zasz, I think they handled the character tastefully.