I always
hate thinking about
possibilities involving
duplication of
consciousness. The
story above would be
similar to someone doing an
upload of their consciousness, waking up still in their
body, and hearing a
voice from the computer go "It worked! Now, destroy the
original."
If a consciousness were to fork, then you have to treat each one equally. Otherwise it's murder, and it's unfair to the consciousness that must be killed.
The toughest part is thinking about being forked myself. I close my eyes, then something happens, then when I awake, I'll only be in one of the two places afterwards. To an outside observer, there are two copies of me. But subjectively, I can't be both. Each one can be me, but I'll only experience life from one. It doesn't matter if the other one is still technically me, from my own view it's not me, since I'm not inhabiting that form.
It's such a messy area, it hurts my head when I think about it.
See: pattern identity theory for one idea.