I pre-ordered and have had a lot of fun playing so far. The story and picking your dialogue choices does add another element to it. If you don't want to deal with cut scenes, then this is not the best game to play since there are tons of them. I'm a big fan of the old KOTOR, Jade Empire, and Mass Effect games, so this is the type of game I enjoy playing other than NCAA Football.
I've made one of each class on one server, but have focused on Jedi Knight for the most part. Every class has a unique story.
I don't remember ever enjoying WoW nearly as much, but that's just me. Not my intention to put down the most successful MMO.
All that being said, there is lots of room for improvements.