I don't think we will be able to resolve it with any amount of knowledge.
It is a philosophical problem, and fundamentally a matter of definitions.
Do you choose to define yourself in terms of a pattern of activity
(consciousness, memory, emotions, etc.), or do you identify with the
specific instance of that pattern which is located in your brain?
Essentially, this is a matter of taste, and no amount of evidence or
testimony will be sufficient to change some people's minds. No matter
how fervently an uploaded person claims to be the same as he was in his
original body, those who define him to be a different person will simply
say that he is mistaken.
What I do expect is that as the technology develops, belief in
the effectiveness of uploading will become more common simply as a
matter of pragmatism. People who accept that uploading (and similar
transformations) preserve their identity will have more options available
to them, and so they are likely to be more successful. As time goes on,
this should encourage more people to adopt this position. In the end,
we will have a minority who are committed to their original bodies, others
who follow some very "safe", gradual forms of uploading, but the majority
will view uploading as no more troublesome than a form of transportation.
Hal