I imagine it'll be easier eventually to simply move the head to an android body.
What would we do with all the spare android heads then? :P
Put them back on our abandoned human bodies so as to allow the machines to fully integrate and understand the human experience as a defense against them misunderstanding our collective craziness and rising up to destroy us. :)
I agree. This is way, way more likely than human transplants, for a dozen reasons. And to be honest, it could be done in a few years. Moving around using the body would be relatively easily accomplished but expression via tapping the spinal cord... not so easy.
One benefit of this is avoiding many sources of cancer, since there would be a whole lot less cell-machinery to go wrong. To me, this seems like the most obvious (though drastic) means of life-extension.
I wonder how to deal with the issue of nutrition and digestion (some sort of synthetic digestive system?), which would be necessary to sustain the brain. Also, how would the head perceive hunger and thirst?