Considering Identity
Philosophy determines strategy - it matters greatly which of the answers to the fundamental existential questions you subscribe to. Consider questions of identity, for example: do you identify with the pattern that is you, or do you identify with the present slowly changing collection of physical structure that is you? If the former, you might consider destructively uploading the data of your mind to a robust computing system to be a fine strategy for the defeat of aging. If the latter, destructive uploading looks like an expensive and ornate suicide method - you are not your copy, and you will not survive the procedure. Doors to the future open or close depending on your philosophical inclinations. Here's a piece that reviews some of the spectrum of philosophical thinking on identity, which has been going on for a good deal longer than modern ideas and technologies have been around: "Star Trek-style teleportation may one day become a reality. You step into the transporter, which instantly scans your body and brain, vaporizing them in the process. The information is transmitted to Mars, where it is used by the receiving station to reconstitute your body and brain exactly as they were on Earth. You then step out of the receiving station, slightly dizzy, but pleased to arrive on Mars in a few minutes, as opposed to the year it takes by old-fashioned spacecraft. But wait. Do you really step out of the receiving station on Mars? Someone just like you steps out, someone who apparently remembers stepping into the transporter on Earth a few minutes before. But perhaps this person is merely your replica - a kind of clone or copy. That would not make this person you: in Las Vegas there is a replica of the Eiffel Tower, but the Eiffel Tower is in Paris, not in Las Vegas. If the Eiffel Tower were vaporized and a replica instantly erected in Las Vegas, the Eiffel Tower would not have been transported to Las Vegas. It would have ceased to exist. And if teleportation were like that, stepping into the transporter would essentially be a covert way of committing suicide."
Link: http://www.bostonreview.net/BR37.1/alex_byrne_philosophy_personal_identity_afterlife.php
While I agree that philosophy is important, especially to the nature and priority of our motivations, I doubt the imminent necessity of contemplating this philosophical issue. The teleportation scenario is particularly far-fetched, since it would require a technology far more advanced than even nano-scale universal molecular assemblers.
Mind uploading is marginally more feasible, but it is not especially relevant to any of the life extension technologies discussed here. It may, however, be important to weigh the prospect when considering chemical preservation of the brain.
All that said, I subscribe to the "patternist" view of identity. The Eiffel Tower hypothetical depends too much on the semantic issue of how we choose to assign and define the scope of nominal terms in our language. This in turn depends on context. Few would doubt that my copy of "The Faerie Queene" is indeed the work by that name, even if it exists as a text document on my computer. In this way, the hypothetical is really a disguised form of begging the question, since it relies on human identity being more like the Eiffel Tower and less like the "The Fairie Queene" when in fact that distinction contains the whole issue.
Mind is not a pattern, but an instance of the energy exchange process. The process model of mind seems much more accurate to me than the pattern model, but I admit that logical extrapolation of both models can lead to nonsensical conclusions. Before we can even start pondering the question of identity, it's necessary to define what it rally means to be alive so that we can understand better what constitutes survival. This remains an unsolved problem.
This question is a science fiction favorite. I'd just like to point out that you are not the same person you were 10 years ago--most of the atoms in your body have cycled out, cells have been born and died, etc. You change, and are literally a different person from moment to moment.
You are not a static object, but more of a pattern wave of material moving through the world. So to take the copy machine to mars scenario, your pattern has been copied on mars and destroyed on Earth. Did you die on Earth? Yes. Are you alive on Mars? Yes. The pattern survived.
To put it in more concrete terms, are you the same person you were when you were eight years old? Physically, you are completely different. IT is doubtful that many of the atoms in your body at 8 are still with you at 48. You certainly have a lot more of them ;) The only thing you carried with you over all that time are your memories.
The Star Trek transporter was explained on the show to read, digitize and send the actual atoms of the person (Maybe like a gamma ray signal) to the planet's surface. There was no receiving machine that would reconstruct the person from different atoms on the planets surface. Some writers saw it working as described here, one show had Kirk constructed with both a good Kirk and a bad Kirk which would would have required new atoms and a software glitch that split his personality. Other shows in the next generation implied that you could use a transporter pattern like a backup, but that was never a regular plot device.
For me it is simple:
I would like to experience the future (100/200/whatever years). Mind uploading won't help me do that. Anything that just recreates a copy of me won't help me do it.
Subjective reality is all I have. Maintain my experience and you maintain "me". Duplicate me after uploading, and "I" continue, in duplicate. Not sure what my feelings toward my copy might be, though.