Forgot to say that I think you should go without him, enjoy your daughter for a while. Your ds will have an AWESOME time staying with Grandma and Grandpa and he'll feel special too and won't know what he's missing. I think your trip will be much more enjoyable without a tantrum throwing, potty training 2 year old.

Not that you won't miss him, and you will feel guilty, but you'll make it up to him at Disneyworld.