Supposedly there are plans for further rides in WS when Epcot finally sees it's love after DHS, but it's not clear where. Martin seemed to indicate there was plans for WS in the not so distant future.
Of course, there's been so many plans for WS over the years and for the most part, they've never gone anywhere. However, with the overwhelming crowds that Frozen will bring to a ride with such short of capacity, I wouldn't be surprised if another ride (hopefully on the opposite side of the lagoon) is built to help alleviate the stress that FEA is guaranteed to endure.