I doubt Skyliner will expand to SSR/OKW/DS. People parking for free at DS and using the transport is already an issue, and it's complete pain right now.
The obvious expansion is Coronado/Blizzard Beach/All Stars. These are massive resorts full of cash guests, and Coronado has a huge convention center.
I can see AK/AKL eventually, with Coronado as a hub, but for now I think getting those huge resorts online for two parks would do more for what Disney cares about, which is bus footprint/$$. I mean, I love the Skyliner, but lets see how it goes when it gets that many more people on it.
You might be right. But there may be a greater incentive to building it to AKL -- AKL basically supports the lowest room rates of any deluxe (lower rack rates that then tend to get discounted even more).. That's largely due to transportation. Stick a skyliner stop at AKL, you might significantly increase demand (and thereby increase room rates).
On the other hand, people looking at the All Stars are looking for the lowest rates possible, and those rooms are generally filling up without much additional discounting. In other words, add a Skyliner stop to AKL, you might find yourself getting an additional $50-$100 per night, per room. Stick a skyliner stop at All Stars... not sure that will do as much to help Disney's bottom line.
If you included stops at Animal Kingdom Lodge AND Animal Kingdom Themepark, then you'd be increasing the value of all the resorts on the skyliner, including AKL, Boardwalk, Beach Club and Riviera. To me, Disney would be more interested in increasing the value of the deluxes as opposed to the values. (The reason people stay in a value is because they won't want to pay deluxe prices. They won't be able to charge an extra $100 per night for a value just because it's on the skyliner, but they might be able to get an extra $100 per night from the deluxes).