Star Wars has a ride at MGM. Harry Potter has an entire themepark. (well maybe not entire park, but doesn't it have its own admission price?)
No, it's the same admission as the rest of the park. The HP theme park is a section of Islands of Adventure. The "islands" at the park are currently:
Marvel Superhero Island
Lost Continent
Jurassic Park
Toon Lagoon
Suess Landing
Wizarding World of Harry Potter
Plus two of the three rides at WWoHP are rollercoasters that were already there as part of the original Lost Continent section, just re-themed Potter-style.
Harry Potter & the Forbidden Journey (the ride inside Hogwarts) is the major attraction. And it's amazingly awesome. I rode it 9 times when I was there.
Plus you can also have lunch at the Three Broomsticks, tour an astonishingly detailed Hogsmeade, take an even more astonishingly detaled tour of Hogwarts (complete with moving portraits and appearances by Harry, Ron, Hermione, and Dumbledore), try stuff like Butterbeer (I had 3 of them - love the frozen kind), pumpkin juice and candy from Hogsmeade, or go to Ollivanders and watch them do the whole wand-choosing thing. They pick a kid waiting in line to do it, but it's a neat little show.
They even have Moaning Myrtle's voice piped into the bathrooms.
By comparsion, Star Tours opened in Disneyland in 1987, and in Disney World in 1992. Both rides closed last year for a major renovation, which was long overdue, and will both reopen this summer.
Both parks have Jedi Training Academy shows for kids, where they can dress up in Jedi costumes and fight Darth Vader or Darth Maul with lightsabers.
Disney World has Star Wars Weekends every spring, which is basically a Star Wars-themed weekend with guest appearances (Jeremy Bulloch and Warwick Davis when I was there), parties and parades in the park.
Star Tours/Star Wars Weekends is fun, but I wouldn't plan a trip to Disney just for the event.
Wizarding World of Harry Potter, on the other hand, I would take another trip down just to see again in a heartbeat.
