Are you kidding? You can pick your parks and list all the things you most want to do, list the restaurants you want to eat at, and even plan your itinerary for each park in the meantime. You won't want to allocate specific days to the parks until the park hours come out, but you can put the framework together. That should keep you busy for a while - then you can post again and let us know when you are done and we'll give you another list of things to do.
How long are you going for and who are you going with? If you have kids with you I can give you a to-do list that might make you wish you'd never asked
It sounds wonderful!