We were there Dec 14 - 17. All the parks were decorated, and at IOA they had a meet and greet with the Grinch. The Grinch used to do story-telling in his lair. This year, no story, but you could still meet with the Grinch.
At USF, they have the Macy's Parade, and there is Balloonopolis (am I saying that right?) set up, so you can see some of the Macy's Parade Balloons and read and learn all about the history of the parade and what it takes to make the balloons, etc.
Also, if you're 18 or older, it's very easy to be part of the parade if you'd like. It pretty much means that you'd hold one of the ropes for the balloons.
We stayed at the RPR, and that was decorated beautifully as well. They had a giant tree and gingerbread houses. I would assume the other 2 hotels did as well.