Yep, I'll admit it, I'm a teenage guy and I watched it (even better, I've read the four books).
I'm not going to say much about the movie, don't want to spoil it for others or give away some of the little problems likely the fans of HP will have with the movie.
For anyone who isn't planning on seeing the movie, let me tell you it's interesting. You can get pulled in by the ‘magic society’ set up. I suppose that is a lot like Ghostbusters; GB started out with the fact that ‘there are ghosts’ then could play around with it, try to explain different things about the supernatural and how ghosts could be captured. In Harry Potter there is a great, and quite believabe (well, you know what I mean when I say believabe) society of wizards, and what they can and can't do with magic powers makes sense.