A few other unique things at DCA:
1. Push the Talking Trashcan: usually found on the path between Redwood Creek Challenge Trail and the Golden Dreams Theater
2. Corn Dog Castle: yum! I especially love the spicy corn dog.
3. Toy Story Mania opens in 3 weeks!
4. High School Musical 2: I'm in my 30s and I enjoy this. There. I said it. LOL!
5. If you have time and your budget allows, the Cruzin' Disney's California Adventure Tour (Segways) is awesome. I did this last December and had a blast.
Good luck with the rest of your planning and enjoy your trip!