GeraldineT - Does your son like characters? I know a lot of kids are scared by the characters at his age. I'd hate for you to plan a special meal for him and have him be terrified the whole time.
Did you know they have a breakfast with Elmo at Seaworld? I don't know what days they have the breakfast, but every kid I know about to turn two is Elmo crazy.
I thought of Arabian Nights, the Pirate dinner show and Medieval Times, but I think he is too young to enjoy those. I know most kids that age won;t be entertained by that kind of thing because the stage area is so far away. I bet in a couple of years he'll be gaga over the knights. (At least my knight and pirate obsessed son was at 4 or 5.) It's pretty loud though - would probably scare most 2 year olds.
The shark dinner looks nice, but I think it is more upscale. not very interactive. I don't know how fun it would be for him just sitting there and observing.
What I would probably do instead of going to a fancy dinner, use the money to take the kids to SeaWorld for a day to see all the animals. Your kids are the perfect age for that, IMO, and you can get better ticket deals at SeaWorld than Disney.