And Sasha's connection--I think (after refreshing my memory via Wikipedia) that the last time Rucka used Sasha she has having her OMAC nanites extracted, so it seems likely he picked up more or less where he left off and had some of those nanites remain or get restored--possibly by Doctor Cyber. Maybe Dr. Cyber worked with what was left over to build her own version of OMAC (and Brother Eye), explaining why it doesn't have the distinctive font or manner of speaking that darkseidpwns mentioned.
I think that's very likely. I'd also like to see Cassandra (she of the cyber neck) involved somehow, though there's not too much evidence so far that Rucka wants to do very much with characters and story elements from Azzarello.Of course it could be both those AND Cyber. Dr Cyber never appeared in volume 2 or 3, so tying her with OMAC could be her new origin story.
Assuming that Brother Eye is involved, I wonder if the event of Futures End will also be involved. If so, maybe the discrepancies in Diana's memory/history will be explicitly linked to Convergence and the crossing over of different realities.