Wife and I went a few years ago. It was a coincidence more than anything. We booked the vacation then found it was Star Wars weekend.
The park was PACKED. I mean, Disney parks in the summer are already bad enough, but it was even worse than usual (wife and I have been to WDW a bunch of times). The park just sort of has a whole Star Wars theme going: Star Wars characters walking around, autograph sessions for some of the minor stars (the main Ewok actor was the big attraction when we went), some speeches from some behind-the-scenes workers, a Star Wars parade, photo sessions with characters...that sort of thing. They also sell all sorts of exclusive Star Wars merchandise and the lines for that were rediculous...literally hours long.
So, if you are not a huge Star Wars fan, you are not missing much. I'm a fan and enjoyed seeing the park all decked out in Star Wars stuff, but I'm not a big enough fan to have to go again.