disney doesnt really do anything perse....however make sure its noted on all ressies. you will get at check in if on site a bday button for him. if youre dining at disney at all he may get free cupcakes etc. there have been the odd story or two of disney magic happening for certain people, this is the exception, not the rule. or you can go one step higher and have a specialtiy cake made- of course for a price. but disney makes some amazing cakes...check out the cake chatter thread. i got dh a cake from 1900 park fare for our anny for 70 bucks. or you can go in and ask for a cake at seating time- called a podium cake for around 30ish.
you can also contact disneyflorist.com and get baskets etc delivered with celebration things, ears, pins, pretty much you name it. i think they will even work with you to add other things you may want.. of course also for a fee!!!
theres also a disney on your birthday thread on here as well with some tips on it.