You say that he went every year as a kid. Did he enjoy it then?
I know that when I was a kid, I got dragged to the beach every year, and I can't stand the beach. I hate sand in my feet, and well, anywhere else it gets....
you know like in Peanut butter sandwiches.
My DW is not the Disney crazed person that my son and I are. (So it's not just hubbies, ladies... I feel your pain!) But Max and I have gone on several father / son trips because of that. She is coming on our trip in April, and it was her idea. We are trying to do other trips for her as well. We just did a non-disney cruise in August of 07, and last year we did a Philadelphia / Washington museum trip too.
Whatever the issue is, you have to try to find something for him to enjoy, and it is not fair for him to "ruin" it for everyone else, particularly the kids.
Disney can be expesnive, but it is not really any more expensive (at least it does not have to be) then other vacations. I know, because we have done our share of other vacations, and in the end spent just as much.