Hi Whitestar -
I think it is even an existential question. If, for all practical purposes, the entity that emerges from the teleportation device is 100% indistuingishable from the entity which stepped into it, it would be the same entity. In classical physics the original entity must perish in the process, which I assume is why you're looking into the ethical issue. If not, you'll end up with a duplicate, not a teleported individual. After only tiny fractions of a second, the two entities will no longer be the same, because they will be influenced by different environments.
In quantum physics teleportation has already been proven. It is not possible (yet!) to teleport a particle. What is teleported is the _state_ of the particle. However, on a quantum level one can argue that the state of the particle _is_ the particle, since the particle is only a manifestation on an energy level. This state is transferred from the first particle to the other instantly (faster than light if the particles are entangled). The original particle loses all memory of the state it had before the teleportation.
So, the difference between classical and quantum teleportation is that in classical physics, you move the particles (can't exceed speed of light), while in quantum pysics you teleport the _state_ of the particles. The outlook for being able to teleport classical objects are extremely slim, though. As syndicated points out, you'd need to teleport an incomprehensively vast amount of information.
Then again, in SF you can of course make up your own rules. A great tip is to go to the Scientific American and buy the online special issue called "Edge of Physics". It's brand new, and has a collection of updated articles on stuff like quantum teleportation. At $5 it's a steal. I just read it - that's why I recommend it.

It mentions a rumor which says that Gene Roddenberry (the guy behind Star Trek) created the Beam-me-up-scotty device to save money (i.e., no need to film all those planetary landings).
Tormod