Hi, Aaron!
So glad to have you heading east to give Disney World a try!
I had the opportunity to go to Disneyland 2 years ago. I visited in July and was surprised how much smaller the crowds were in Disneyland vs. Disneyworld. I could have timed it just right, but we were able to walk on rides such as Soarin' which almost never happens in Disney Word!
However, I think the biggest difference you are going to notice is the difference in size. Disney World is just huge! While you can basically walk from any 3 of Disneyland's Hotels to either Disneyland park, Disney World is a city in itself! You will be amazed by the resort, restaurant, and park choices. (And wait until you see the size of Cinderella Castle, its going to be quite a site for you!) Make sure to call ahead within 90 days of your stay to book your dining reservations at 407-W-DISNEY.
So, yes, you will see larger crowds when you come to Disney World, but you are coming at a good time so hopefully the crowds will be manageable. Look through
www.disneyworld.com to make notes of rides that you can't do in California so you have all new experiences. Just going to Epcot will make your trip worthwhile.
We truly enjoyed Disneyland. It was so charming and magical. But I think you will find Disney World to be just awesome!
I am sorry to say that I am unaware of any discounts that would apply due to your Disneyland Annual Pass.
Welcome to Disney World, and have a great vacation!