Hrm. I have to wonder is there much point to even ponder this? Look at our technological trends. Between expansive computing which we might end up actually plateauing to the point we can reason that despite their ability to perform equal or greater calculations than the mind can never form sentience and we say fuck it we did all this work, if they cant have the "mind" we will be the mind for them and begin integrating our minds into omnipresent network systems or into mechanized forms. It might be even within the scope of some of our lifetimes that we will have leapfrogged well beyond the notion of no plausible physical representation.
It will be at that point where we have to make very difficult decisions that forces us as a species to value quality of human life instead of quantity because with capacity to transfer, upload, download a mind into a hive mind network, into a corporeal robotic android frames, cyborg reclaimed bodies, Or even possibly clones from your original DNA that have been stored to perpetuate your existence through the ages(Sort of a process akin to what Whedon posited with Dollhouse) We will have to come to grips with the truth that with the capacity to live for ages that it is impractical for human biological reproduction to continue as it currently does simply because it is not practical. The number of "entities" in such a world would essentially have to have severe limits or even in virtualized server space the sheer magnitude of reproduction with nothing to effectively cull and thin the herd would simply lead to deterioration in any form it would take. For sort of an example look at something like the over arching premise of "Torchwood: Miracle day" Where death ceased to function and just how quickly such an ominous threat could begin to manifest in crisis and catastrophes.
So realistically we would have to deal with far greater problems, and realistically It seems more feasible that by the time we would have an effective means to allow someone to live in such limbo, that we would also have more than developed methods to work around having to endure a completely non corporeal existence. At least I would think.
