I think that we know Zoe. She might have Ben on the island already. Reasons: 1. Why the heck did Widmore hire Zoe? Okay she is a geophysicist but still, there might be anther reason. 2. She knows her way around the island pretty good. 3. Maybe when Sawyer came to the Ajira Plane, Widmore and Zoe awaited Ben to come. Zoe may be Annie?
(This is VERY random thought, so don't take it to seriously)