I dont know if anyone noticed, and if the scanlation is 100% accurate, but Sasori said (p.10) that a "subordinate of orochimaru" is a spy of his. I think it cant be Sasuke but what about Kabuto?? Kabuto is known as a spy so, in traditional Japanese fashion...
"Could it be..." LOL.

Maybe Kabuto has some tie-ins with Akatsuki.

The Sharingan thingy is all speculation until Kishimoto explains it. Maybe it is an under-developed mangekyou or something! who knows!