Right now Disney needs to do some major updates, especially in Hollywood Studios. They really are lacking in anything modern/relevant there, and while Uni has somewhat of the same problem it is still updating (Harry Potter). Yes, Disney is doing that Avatar land thing, but I don't see that really being overly big, at least not as big as Harry Potter was able to be for such a long time.
A big problem for Hollywood Studios is Disney hasn't had a good show on ABC for who-knows-how-long, and that means having to bring in the American Idol part, which doesn't matter since the show is pretty much dead at this point (and has been for a while). Indiana Jones, while a cool show, really hasn't been relevant for a while, and the 4th movie basically ruined a come back. Even the back lot tour feels dated, especially since they had to take stuff out for the motor show (which is cool, so that is excused). What is up with the Narnia attraction, it's just a trailer for an old movie? The Toy Story ride is very fun, and I'm glad Pixar is getting more of a role there, but really, it's not like Disney doesn't own a bunch of movie companies and ABC, they really should have more to do there. Plus, the park pretty much closes when it gets dark out, as that's when the shows end. Overall, it just needs to be updated.
I think that's a problem with a lot of WDW right now, it's like the framework is all there, but in spots it really needs to be redone, and please, why won't they do something with that weird, always empty eating spot in MK to the right of the ice cream shop (it bridges main street to Tomorrow Land, I think it used to be a noodle station or something). Stuff like that just makes the park feel abandoned at times, leaving for an odd feeling.
That said, I still prefer WDW, as I'm not a big roller coaster person and I grew up on Disney.