The best information I have, nothing really official, but from multiple sources who are in a position to know:
AKV (as announced)
DL
Contemporary
A
Disneyland resort could be announced and built concurrently with AKV as there is really no conflict between having two resorts for sale at the same time.
I would suspect they wouldn't announce the next WDW DVC resort until AKV was well into it's sales. This would be their best guess on when AKV would sell out, and the timeframe to having another resort ready for new sales.
Based on past history, it appears DVC has learned a lesson in not having a resort to sell, and will attempt to always have the next resort available for sales before the previous resort sells out.
Personally I would not be surprised if an EP resort comes before a Contemporary one. Some of the initial ground work for EP had already been done. It would all depend on construction costs and construction timeframes.
Of course, Disney always keeps their options open, and a lot could change in the next few years.