A shuttle seems a little far-fetched to me. That's an awful big expense for 4 months when there are other swimming options available at OKW.
The only thing that may make some sense is if they were to combine a normal bus route for SSR and OKW--like maybe the Downtown Disney route. Maybe they would consider having the DD bus go from OKW to SSR then to DD. Of course, that would make for one heck of a long loop with multiple stops at all three locations, plus the normal trip over the Typhoon lagoon.
More likely, I suspect the boat may be the only direct transportation from OKW to SSR.