Some places that my parents really got a kick out of -
Breakfast at the Fountain View Cafe at EPCOT. As the name says, it's to the right side of the big fountain just past the EPCOT globe. Great coffee, great view, you get to watch the fountain go in time with the music.
Resturant Akerhaus at Norway, the buffet at Germany, and the boat ride in the Land. We also went on the additional tour at the Land, it was very interesting and realtively cheap.
Another thing to consider are some of the tours that they have in the parks. My mother and I went on the Secrets of the World tour in EPCOT, had a great time. Lots of walking.
My mother is pretty heavy and it was very obvious that she was not going to be able to do any serious distances so we rented an electric wheel chair for her (from a non-disney company, they delivered right to the resort, NO problems, easy to use, overall GREAT!).
The animal kingdom overall was a hit.
Over at the MK the riverboat was a big hit, along with the haunted mansion and the pirates of the caribean. We unloaded my father out of the boat like a sack of potatoes, it was pretty funny.
Have a great time!