Walter may still be alive.

Timmy the ultramorph

Disagree. I think - this is was a Walter. Cabin on the lake? Not argument - Walter just decided not to speak about it. This is meas that Walter accept David's ideas & refused the past "slave of duty". Valhalla - same.

Or it was a David AI in Walter's body. And in AW we will see struggle of two minds. But this also means that David's body is dead.

Or it was a David AI in Walter's body

If they go that route, I would think Walter AI would be in David's body. Walter's wounds healed except for his arm. He was stapling his face near the end. Seems Walter's body would self heal for an abrasion. Walter could have tricked MUTHER by requesting the music at the end- playing the part of David? That way, there would be no suspicion from MUTHER. Then again, the access code seemed to be all that mattered to MUTHER.

The is it Walter/David is something debated a bit before, but Ridley Scott had confirmed that David had disabled Walter and taken his clothes and then cut his own hand off.

I think this is the story that RS/FOX will stick with, HOWEVER.... i cant see Fassbender playing the role of a ONE Handed Android in the next movie, at the very least i suspect David will repair his hand with the use of SPARE PARTS taking ONE Synthetic on such a IMPORTANT mission knowing the tasks that Walter can perform, i would doubt they would not have any SPARES about.

We CAN-NOT rule out however if David is able to actually BUILD a Walter from Parts and then UPLOAD his Memory/Soul into this Unit, i think this is something very possible.

As far as Walter, i think again its likely we may see him or if not, it will be inferred to us that the Engineers came across him, they would discover he is not HUMAN but there would have to be some good reason they dont go to Earth or check out LV-223 as i think they will indeed head to where David is going and i would assume they turn up on Planet 4 a Long time after David has left.. otherwise we could safely assume they would intercept him in no time at all.

I recon the Engineers dont turn up on Planet 4 until David has been on Origae-6 for quite some time.