My opinion doesn't mean a lot, being a DVC member for all of 2 months and having ZERO stays under my belt. Nevertheless, I would be SHOCKED if the next DVC property was not associated with an existing property. It only makes financial sense. If they added-on at AKL or Contemporary, they don't have to duplicate all of the infrastructure that is already in place (registration, pool, dining facilities, etc.)
In building SSR, at least the were able to make use of some of the Disney Institute facilities. Since the DI was going nowhere fast, and the Pop Century debacle proved they don't need another on-site resort, DVC was probably a logical move for that property.
I'm not personally familiar with the evolution of Eagle Pines. I've seen the press release, but have little understanding of what occurred to derail that project. 9/11 perhaps?
But if I were a betting man, I'd put my money on the Contemporary or AKL before EP moves forward.