This year will be our first one too. Our vacation is in a couple of weeks - it will be weird to be celebrating Halloween in August. Personally I think Disney is pushing things a bit too far, but I digress.
In any case, we are going to get dressed up. The original plan was to do the Inside Out characters (perfect for our family of five) but there's not enough time to get together what we'd need. So we're going to be extremely boring and just wear Incredible t-shirts.