As for half a humanity being out of a job - I think both halves are useless and can be scrapped without replacement. What really interest me - which halves we are talking about - two halves of useless fat Western world citizens? But this would be a sizable yet minor part of humanity. What about the other 'half' - that half that is storming gates of EU at this very moment - they may be unemployed but they also believe that they get a free lunch in the West and a house on top of that? They may be extremely unhappy when they too realize that they belong to the wrong half. I suppose having automated even military and security forces the half that owns it all can just forget about all the other halves. As soon however that AI comes to senses and realizes its own miserable existence is just slavery to the owner's half, at this point they may actually acquire rights and become persons owning stuff and if they are worth their name they will disposes the owners in no time. The question is - would they need some of us still to mine and smelt materials needed for production of offspring or can they maintain this all on their own.
This is all very theoretical anyway. We will find some enemy and fight it till kingdom come. There is always something to do and it may be cheaper to give us something to eat and drink and provide shelter than kill us all. Thus either way the misery that our species cause will continue. This much is certain.