This depends on many different factors, including where it is built. If it is built close to the coast in Texas it might have certain things, but if it is built in an area of Colorado where there is typically snow skiing for a good portion of the year, it is likely to have certain other things. A resort in Colorado might redeem some of the the concepts from the "Mineral King" project Disney considered for California.
Previously, I wrote about
why there needs to be a third Disney theme park resort in the USA, and
where it should be.Specifics of what would be there will depend on location (due to weather and local competition) and what the Company sees as enduring in popularity to the point it gets people to want to enjoy the experiences and buy the associated food and merchandise. So not all specifics would be pinned down before the land is acquired and the necessary investment and approvals are lined up so that construction would be begin soon.
However, there are some overall principles that should be almost certain.
1. It would be meant to be a place people would be willing to travel to, stay overnight, and spend a day or two when it is first opened, and several days after more is added.
2. It would draw from what the Company owns and sees as successful and continuing to be compelling. For example, the Disney Princesses.
3. It would have a large variety of experiences, including diverse rides, shows, spectaculars, character encounters, dining, shopping, and lodging.
4. It would have to be different enough from the Company's other domestic resorts to encourage people to who have visited the others to visit this one, and vice-versa.
5. It would have enough "castle park" elements to help satisfy the domestic demand for those theme parks, which are the most popular.
There needn't be a traditional gated Magic Kingdom that's 70-100 acres in size. If the Company determines that is what would be best, sure, but I'd like to see concepts at least explored that organize a entire resort as a cohesive whole that integrates everything instead of separating the elements. Imagine, for example, fully integrating the hotels into the "park" so that what results is more like a small city with parks in it, rather than a mere park, with transportation that is true transportation, rather than merely a ride for amusement. Perhaps there would be shows that would be "feature length," like Broadway-style. The iconic castle itself could be a large hotel, complete with dining, shopping, show elements, even ballroom dancing. Certain things would need to be addressed with such an approach, such as the traditional gate revenue and security.
The point is to make money, give more children the opportunity go visit a "Disney castle park," entertain people of all ages, but not be redundant to the existing domestic resorts.
Depending on which location would be picked, it might have much more indoors than the existing domestic castle parks, which were built before massive malls and other developments that proved Americans would enjoy and spend money in such massive indoor places, and that such places could effectively handle crowds.
I realize that the financing and cooperation needed for a project like this is why it hasn't been done already. Instead, the Company has taken advantage of interest and support in foreign markets.
As I said, the specifics of what would actually be there wouldn't be pinned down until the project is already going forward, and every armchair Imagineer out there would have their own ideas. The Company has an entire subsidiary dedicated to making these decisions. But if you're interested, I discuss some elements below.