Here are ideas that might work for your group. I think you'll love the Vistana too. We haven't stayed at the Villages, but have stayed at the sister property the Vistana Resort four different times with our multigenerations group. You'll enjoy some relaxation time at the pools I'm sure too, and look to see too if any of their organized activities have any appeal to you. The resort puts out a weekly schedule, so I imagine the Villages would too.
1) OK it's a theme park but so much different than Disney. The grandparents and parents in our extended family group love the beautiful grounds, outstanding shows, and animal exhibits. // DS 16 loves the animal exhibits, two fun coasters (my mom, brother, and I love these coasters too), wonderful shows and is going to a high school aged camp here this summer. My nieces and nephews have always loved this place too. It was DS's favorite park at age 3 and is still his favorite at age 16.// This is a better park for a multigenerational group than Disney parks IMHO and our family's favorite. // Oh and with an eight year old the Shamu Happy Harbor play area is so cool -- it caters to elementary / older elementary and we took our kids to that through age 12. // You can also get day 2 free in a seven day period if you want to come back by just stopping at the customer ticket window. (I see it's a favorite of one of the other posters who responged too).
2) Resort Hop at Disney -- Visit some of the Disney resort hotels and walk around. We like to park at the Polynesian walk around there (Just say you are there to shop or eat and they will give you a three hour parking pass), take the monerail over the the Grand Floridian and Contemporary and walk around those -- stop in the gift shops at each, at the Polynesian maybe pick up a Dole Whip and sit our by the pool or beach. Depending on how much time we have, we have sometimes taken the little boats over to Wilderness Lodge to look at their grounds too and see the little man made geyser they put in. // On a different day we like to do a meal at the Animal Kingdom Lodge and walk around their grounds before and after and look at the animals. The main lobby of the hotel is spectacular too. // good for all ages
3) We like Gatorland too. It's a three hour attraction -- Think more old time Florida attraction and maybe a little cheesy vs. World class theme park, but it is a great break from "World Class theme parks", something a little different and a good time. It's excellent for a multigenerational group too.