I thought this game was fairly well done in respect to the original.  The basic concept remained the same, (I'm in a mall-like structure, I need to save people, and gradually uncover what's going on) and the gore was maintained.

Yet, I couldn't help but get slightly bored after using many of the new weapons. Yes they're creative and effective, but killing zombies is killing zombies. After killing enough in order to get the Zombie Genocider achievement, it became monotonous when plowing through zombies.

Although this is just my opinion.

Overall the game is quite good, and has a fairly intriguing story to figure out.

I'd say this is a definite buy for newcomers to the game, and a sure-rent for veterans.