I'm with most people on this post. I would never do it in my own tank, but I'd be pretty interested in seeing how it turns out in someone else's.
I don't think I'd ever do a theme tank, I just prefer things to look as natural as possible, but I can't argue with anyone who wants to do something different with their own tank. I remember someone else saying they wanted to (but hadn't yet) make a football-themed tank where GSP made the grass, some forked SPS made the goal posts, and zoas or something made up players on the field.
If you can pull it off and it doesn't look sloppy, I say go for it.
At the end of the day, it's all about what makes you happy. If Star Wars in your reef tank gives you passion, you're on the right track.