Some trips we go to a park, some trips we hang out at the hotels.
Exploring the resorts is great fun. Just taking the shuttle boats between resorts is relaxing and enjoyable. If you are going any time between Thanksgiving and NYD, they are all decked out in holiday décor. And I mean VERY decked out in all kinds of surprises. In some ways the gift shops are all similar but each offers some unique items. The Boardwalk has a nice art gallery. The Grand Floridian has live music every afternoon. Most have a nice place to enjoy adult beverages, or a leisurely meal. You'll also see art, nice walkways, and ideas for a return trip.
If the weather favors swimming, most resorts have nice locker rooms for storing items, showering and getting ready. You might want to keep your hairdryer/brushes/toiletries handy. I don't relish wet suits, but we ALWAYS travel with some oversized Ziploc bags, so it is very easy to stow them.
There are also many shops at MCO. If you have time, I suggest McCoy's (up in Hyatt) for great food.
We usually have our own car, so we often like to have a meal offsite on our last day. (better food, lower prices!) In addition to WDW options, you could easily drop by Citywalk to explore. (Universal is closer to the MCO airport than WDW.)
If you are at a hotel with a marina, and even if you aren't, you can also rent a boat. Some also have carriage rides.
If you really want, the area has plenty of taxis to get around.
Water parks are okay, but remember winter weather an be downright CHILLY. I've even had to scrape hard FROST off our windshield! In winter, WDW closes one of the water parks and the water rides, because so few folks want to get wet. Some folks will swim in any weather, and the WDW pools are heated. Hot tubs can be okay if your hotel has one.