There wasn't supposed to be anymore big screen Star Wars movies, but I guess that didn't include animation films... But don't be mistaken, this is a Star Wars films, including major characters, story continuity and look. Most voices are from different actors then from the movies, except for Samuel L. Jackson, Anthony Daniels and Christopher Lee.
If you saw the first Clone Wars cartoon from a few years ago, you will be in familiar territory. There's a unique style to the characters' look, which is quite interesting, but I found that the animation was a little rough sometimes, not as smooth as it could have been. But that wasn't enough to spoil it for me. I liked this movie, with it's story and style. It's funny, fits perfectly in the Star Wars theme and we get to discover new characters. Possibly because it's a cartoon, the tone is much lighter then the movies in this time period, despite the fact that they're in a war.
If you didn't know, there is two TV series coming based on Star Wars. One will be live action and one will be a cartoon. The Clone Wars is basically the pilot for the cartoon one, but they will probably be able to finance the series with this big screen version. I don't think Marketing ever sleep at Lucasfilm...!
I don't know why people don't seem to like this movie. Maybe they were expecting too much from a cartoon. Maybe I'm not normal. Maybe a little bit of both. I don't care. Your loss. :-P