There are birthday pins available in the parks, I've heard that folks wearing those get extra attention. Or, you could make him an "It's my birthday!" T-shirt, for extra visibility.
Just wanted to find out what your expectations are when you say you want them to "make a big deal" out of his birthday. A huge percentage of the people at WDW are celebrating some special occasion, so they simply can't do something for everyone.
I've seen too many people come back disappointed from a trip because they had a birthday, and expected something magical to happen, and nothing happened at all.
The most you'll get at the resort is a signed picture of a character and some balloons, and that's not always done. They may not acknowledge the birthday at all.
He MIGHT get a birthday cupcake at some restaurants, and if he wears the button, he'll certainly get a lot of "happy birthday's" from the CMs.
If you're looking for something more tangible, like a cake, or having your room decorated, you'll need to arrange and pay for that yourself.