If you're a fan of the original, or just want to make better movies, the expansion is a must-buy.
The Freecam Mode in Custom Scriptwriting allows you to control the camera in a scene, and the game does a good job of it.
While the Stuntmen occasionly become an extra chore to handle (by having to constantly train them while at the same time making your actors/directors happy), they bring with them plenty of new, over-the-top scenes to add to your movie, along with brand-new sets and costumes such as the green screen set.
Above everything else, this game is simply a must-buy if you liked the previous game, and it adds plenty to the already-innovative game.