The only area I think may be appealing would be a ski resort. Skiing attracts many families. When i ski I like to have a bigger room. Maybe on a Caribbean Island but too me thats not all that appealing. I would rather see more studios with two queen beds.
Caribbean is too boring. So many people have been there-done that. Harder and more expensive by air than a mainland vacation. Way too well covered by cruise ships, so it would be a tough sell. Why buy DVC when cruises are so cheap? And, where in the Caribbean would you suggest to build a resort that will be more popular than Aulani?
As for ski resorts, I think that is a big, BIG mistake that will make Aulani look like one of Disney's favorite properties. Yes, they are very popular with families, but there are a few things to consider:
1. Not everyone skis. This very much limits the purchasing pool.
2. Skiing only runs from maybe November 1st (if you are very lucky) until the end of April.
3. Most ski towns are small, deep in the mountains, and, when not skiing people will, do what?
People could ski all the way through May, but most ski resorts shut down, due to lack of interest by that point. From then on, it is mountain hiking. MAYBE a bit of nearby fishing, and? Who wants to just go spend a week in a lodge in the mountains where the main entertainment will be hiking in the hills for a few hours a day, and watching TV.
Keep in mind the altitude of most ski resorts is up around 8000 feet and a lot of elderly people have trouble breathing at such altitude. Not likely to be a popular vacation with Grandma and Grandpa.
And, when not skiing, the mountains are really most attractive for only 4 months - June, July, August, Sept. In May there is probably still too much snow on the ground and in October it is getting cold, and sometimes wet, but not enough snow to ski. I will also say that sometimes, up around 10,000 feet, you can even get major snowstorms in mid to late August. You would generally need a car to get around and go out to nearby towns, restaurants and such.
So, almost no one is going to want to buy all those days from May 1st through November 1st, but Disney will need to sell them, to pay for the resort. How many people are going to buy a DVC Ski Resort, just so they can ski, and then find out that there are twice as many skiers as there are ski days available to book?
Don't get me wrong. I live in Salt Lake City, only 40 minutes away from many world famous ski resorts, but I think trying to build a DVC property at a ski resort would be a disaster of epic proportions.