Depends how you define upload. Why couldn't a computer just simulate a persons outputs based on recordings of their life. Does virtualization of life really need to have consistent consciousness? Maybe rip would be a better word than upload.It would require something along the lines of the Allen Brain Atlas Project [0], but much more advanced, since you'd have to extract all the information out of one brain. The Allen project has several atlasses, built out of different brains. They've yet to map the circuitry of a mouse brain (the project was started in 2011).
Even if it were possible to extract the relevant info, since the extraction would destroy the brain, you'd better have a conscious clone, which preserves the identity of the original. What happens to one's identity is also troubling, since you could, theoretically, instantiate several copies of someone. I'm not sure the identity would be carried over, actually.
By identity, I mean the fact that you're the same person in the morning that you were when you fell asleep. Your consciousness dissolves and re-emerges, and you're still yourself. We take it as granted, but it is extremely puzzling to me.
Another problem is that the relations between time and consciousness have yet to be understood. The fact that the brain processes information in parallel is probably important, meaning that a fast serial simulation by turing machines would not necessarily cut it, even with "massive" supercomputers. The level of parallelism in the brain will not be achieved in a long time in silico, at least not with the current approach.
[0] http://en.wikipedia.org/wiki/Allen_Brain_Atlas
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Side note: you should remove the four spaces at the beginning of your post.
To Be: http://www.youtube.com/watch?v=pdxucpPq6Lc
See also the Grandfather's Axe paradox, aka Ship of Theseus: http://en.wikipedia.org/wiki/Ship_of_Theseus
A longer piece, Mechanisms of Mind Transfer: http://www.mind.ilstu.edu/curriculum/extraordinary_future/Ph...
Regarding the Ship of Theseus, our identity is most likely tied to an ever evolving process that depends on the architecture of our brains rather than a fixed set of molecular components. Beside the neuronal DNA, most if not all cell components are subject to a turnover.
Greg Egan is one of my favourite modern sci-fi writers. He explores interesting and hard ideas about what it means to be human by placing humanity in thought provoking situations.
In 'The Jewel' we have developed an implant that learns how to 'be' the host. At some point your brain is removed and the jewel takes over your functioning. The thing is, what happens when something goes wrong... boom boom booooom!!?!?!
But really, read him if you are into sci-fi.
[0] http://en.wikipedia.org/wiki/Greg_Egan
[1] http://en.wikipedia.org/wiki/Axiomatic_(story_collection)