The official Collector's guide made hints that Desmond could now be existing in a state similar to Juno was after his sacrifice; I mean, it's possible, right? That technology could surely preserve him after it destroyed his body.

So - Desmond living as a digital hologram, confined within the Grand Temple. Do William and the others come back to find him? Does he search within the abandoned Animus and reconstruct Clay? Can he communicate through the Pieces of Eden like Juno did? Or maybe he's just alone and remorseful...