No problem, just be like "So we're also going somewhere else on this vacation and here's a few videos that just might give you an idea as to where we're going..."
One thing we did that was fun for my dd's and grand daughter is we bought teiras(sp) at clairs for them to wear at disney land so they were all princeses- my girls were 13, and 16 and 6. It was so fun and people would stop us to ask where we got them.
I haven't read through every post throughly, so forgive me if this has already been mentioned. Do you know about the Jedi training academy? I've included a link below for you to check it out. If your girls do Libby Lu and you want something special for your DS to do, this is so much fun! Or maybe all 3 would want to try? My DS did it in May and it was great! Also, another special thing that I read about in a different thread is to leave little "Tinkerbell" gifts (You can word it differently for a boy), on their nightstand at the hotel so that they find them in the morning. A lot of dollar stores and Target stores have some really cute dollar items relating to disney characters. The Target store near me has some really cute "Cars" items right now and sometimes has some princess ones too. Have a wonderful trip!
Didn't read the posts, but don't forget the Princess story time. It was in a store near the castle. Goofy's Kitchen and Ariel's Grotto have character dinners - that way you can catch the rides in the morning and still do character dinners. There's an area in DCA that's fun for younger ones, as the rides are not so big (the older kids will probably not enjoy it though). Have fun!
I went this past November and it was HOT! I only brought winter clothes and my husband had to go to Target to get some tops and shorts for me and my kids to wear! You might need a light jacket at night but that's it.