ankokudaishogun said:
...you'd think a massive head trauma would LESSEN Sasuke's chance to survive the Cursed Seal.
Also, Orochimaru doesn't care too much about the Sharingan itself, as much as he craves Sasuke's superior body .
Given what we know now, it seems probable that Orochimaru intended to possess Sasuke, then implant himself with Hashiramas DNA just like Madara, and awaken the rinnegan. Kabuto certainly implies that they were researching/aware of this. Orochimarus ultimate goal was probably to become what edo!Madara is right now.
As for the basic idea. It would make more sense to hang around covertly after placing the seal to observe if Sasuke lives, and then take his corpse for eye extraction if he dies. Infact, Kabutos convenient appearance may well have been for that purpose. Orochimaru may have ordered him to help the team pass if Sasuke lived, or kill Naruto and Sakura and run away with Sasukes corpse if he died.
Still, if we go by the idea, it is worth asking. Does Konoha have any spare sharingans in storage? I mean given that Kakashi has proven that sharingans can be helpfull, you would assume that a shinobi village would have extracted atleast a few sharingans from the dead Uchiha and put them to storage.
Or heck, what would happen if Orochimaru did take an eye, and Kakashi decides to give his sharingan to Sasuke, knowing it will work better for him and remove Sasukes desire to go to Orochimaru. How would Sasuke react once he realises that the eye he got from Kakashi is actually a Mangekyo Sharingan.
Or maybe Itachi realises that with Sasuke having lost an eye, his plans of suicide by Sasuke are ruined (he would find it hard to fake a realistic life&death battle against a "crippled" Sasuke), and so he fakes somekind of attack on Konoha where he is "overwhelmed" and killed. Maybe attack Jiraiya or somesuch on the pretense of kidnapping Naruto and then make sure he loses in a way that leaves his head intact. That way Sasuke can get his eye (which could lead to Sasuke awakening an EMS pre-timeskip).