I believe that if/when uploading becomes feasible, few will be interested if it means the destruction of the original because they will not be convinced that it will "still be them". It'll be a different story once uploading without destroying the original is perfected. However, for those pioneering few who choose to allow themselves to be destroyed in the process of uploading, the question "Will I survive?" becomes entirely moot. We are no more likely to determine the answer to this question than we are to determine the existence of god. It's a waste of time to ponder whether the original identity survives "as" the dupicate. The facts are that the original is gone and we will never know.
I agree with Robin Hanson who suggested that not enough consideration is being given to the perspective of the uploaded entity. I would be concerned with how the copy would cope with all this. Assuming they're uploaded with the same emotional proclivities as the original, how would they deal with the feelings of doubt and guilt as they question the very validity and meaningfulness of their existence? Yes, you would feel just like the original, BUT you would also know that you could never truly know whether you are deluded or not. In addition, how comfortable would others be interacting with you now. In the early days of uploading, I imagine most people will think of you as "not the real thing. . .but an amazing simulation". How will this effect your successful adaptation to your environment? Will your family and friends grieve the loss of the original or really accept you "as" him. There's a great potential for isolation, depression, anxiety, etc. As Robin indicated, these matters are more salient and meaningful than debates over the unknowable (I hope I'm not mis-characterizing your comments, Robin).
This brings to mind my earlier post on personality enhancements. If I were being forced to undergo uploading (for some reason), I would anticipate the potential problems of me or my copy (whichever) emotionally handling the transition and if possible try to minimize the trauma by arranging to have my emotional intelligence enhanced/optimized in preparation.
Scott