Overrated, it was good, but not THAT good.
Story: Uninspiring, but wraps up the series fairly well. (Not sure if they will actually end the series due to it's success)
This movie is pandered towards existing fans, so if you haven't watched the Haruhi series, I wouldn't recommended this movie until you do so. The movie presumes that you already feel for the characters, understand the interactions and relationship between the characters.
Don't expect to:
Cry your eyes out
Smile the whole day
Be left with any kind of strong emotional feeling after watching this movie. The movie leaves you basically the way you felt before watching the anime. The movie lacks passion.
Characters: Crazy whacky characters with personalities an inch deep.
You can throw in a ninja samurai warrior, a succubus and a witch into a story, doesn't automatically make the characers interesting. The problem with the anime series is that it's focused on Kyon, a normal, regular highschooler, he's also BORING.
Overall: Enjoyable movie. Not a movie that went well beyond my expectations. Not memorable nor inspiring. Just another movie to watch and forget.