TheOtherDave, you seem to be implying that Locaha is unusual in not being able to experience Bill Gates's reality, and that in principle it should be possible to "identify with" Bill Gates and then suddenly "wake up" in Bill Gates's body with all of his memories and whatnot, thinking that you had always been Bill Gates and being none the wiser that you had just been experiencing a different body's reality a moment ago.
If that is possible, then how do we know that we aren't doing this all the time? Also, if this were possible, then we would not really have to worry about death necessarily entailing non-existence. We would just "wake up" as someone else that next second with all of that person's memories, thinking that we had always been that person. (Of course, then that begs the question: who would we wake up as? Perhaps the person with the most similar brain as our former one, since that seems to be how we stick with our existing brain as it changes incrementally from moment to moment?)
I don't think Locaha's inability to experience themselves as Bill Gates is unusual in the slightest. I suspect most of us are unable to do so.
Also, I haven't said a word about Bill Gates' memory and whatnot. If having all Bill Gates' memories and whatnot is necessary for someone to be Bill Gates, then very few people indeed are capable of it. (Indeed, there are plausible circumstances under which Bill Gates himself would no longer be capable of being Bill Gates.)
Scott Aaronson has a new 85 page essay up, titled "The Ghost in the Quantum Turing Machine". (Abstract here.) In Section 2.11 (Singulatarianism) he explicitly mentions Eliezer as an influence. But that's just a starting point, and he then moves in a direction that's very far from any kind of LW consensus. Among other things, he suggests that a crucial qualitative difference between a person and a digital upload is that the laws of physics prohibit making perfect copies of a person. Personally, I find the arguments completely unconvincing, but Aaronson is always thought-provoking and fun to read, and this is a good excuse to read about things like (I quote the abstract) "the No-Cloning Theorem, the measurement problem, decoherence, chaos, the arrow of time, the holographic principle, Newcomb's paradox, Boltzmann brains, algorithmic information theory, and the Common Prior Assumption". This is not just a shopping list of buzzwords, these are all important components of the author's main argument. It unfortunately still seems weak to me, but the time spent reading it is not wasted at all.