Awww, it's so great that you're going to spend his birthday there.
Here are a few cool suggestions:
1) If there isn't a birthday pin waiting in your room for him or given to you at check in, go to guest services at the first park you go to and tell them. They'll give him a pin and write his name on it. Cast members are trained to look for the pins, so they'll wish him a happy birthday everywhere he goes. He can wear the pin during your whole trip, not just on his birthday. This is a must. He'll get so much attention he won't know what to make of it all.
2) The Pirates League located in the magic kingdom. This just opened this year, so I don't know if you've heard of it. It's a little expensive and you need reservations, but basically they can turn your son into the pirate of his dreams, costume, makeup and all. He can be a skeleton pirate, Captain Jack, or Captain Hook. They have a few different packages. Here's the link and the phone number to book it - you do need reservations
http://disneyworld.disney.go.com/tours-and-experiences/pirates-league/
3) Disney's Pirate Adventure
Disney's Pirate Adventure is a 2-hour sailing adventure for children between the ages of 4 and 12. The adventure takes place Monday through Saturday from 9:30 a.m. to 11:30 a.m.
At the start of the Disney Pirate Adventure, children are given a Mickey Mouse-inspired pirate hat or bandanna to wear as they make their way onto a boat, which is bedecked with a high-flying Jolly Roger flag blowing in the wind. Setting sail, the group takes off to exotic ports of call—nearby Resort marinas—as they join In a hunt together to collect buried treasure.
During the expedition, participants will enjoy lunch (which includes a peanut butter and jelly sandwich, gummi bears, krispy treats and juice), learn how to talk like a pirate, and—if they're lucky—return with a bag of genuine pirate booty.
For reservations up to 90 days in advance, please call (407) WDW-DINE or (407) 939-3463. Guests under age 18 must have parent or guardian permission to call.
4) Character meals and make sure you tell the reservation people it's your DS's birthday.
Chef Mickey is always a favorite at the contemporary resort - the characters are Mickey, Minni, Donald, Goofy, and Pluto
Garden Grill at EPCOT in the Land - This one is chip and dale
Crystal Palace at MK if he likes Pooh and friends
Ohana's for breakfast at the polynesian - this one has lilo and stitch
Hollywood and Vine character meal - Playhouse Disney characters
There are tons of other dining experience. Some are character and others aren't. But those are some of mine and my nieces favorites.
5) There's also the mainstreet barbershop in MK. They can give your son a cool hair do that's not too expensive, but sometimes there is a wait. I've seen pictures where the kids have mickey's colored into their hair and lots of gel and spikes and glitter. It looks pretty cool.
6)Customize your celebration page
On the left, narrow down the search to birthdays and you'll see all sorts of stuff that you can do.
http://disneyworld.disney.go.com/celebrations/customizations/
7) Disney gifts and florist. They have tons of birthday stuff that can be delivered to your room on his birthday
http://www.disneyflorist.com/category/occasions/birthday/display
8)Mickey Gifts
Buy little Disney themed stuff at the dollar store or Walmart or the
disney store while your home. Wrap each one (have one for each day of your visit) along with a typed note or birthday card from a favorite character (different one every day, or the same one if he has a truly favorite one). Set them out so he'll see them first thing in the morning or right when you return from the parks each day. It's sure to put a smile on his face.
Hope some of these help. I'm sure your son will have a great birthday at WDW
