Some people aren't realising that yes, for most extents and purposes, the copy would be you. If you went home to your mom after teleportation, she'd have no reason to love you any less or treat you any different. But those with even the simplest knowledge of computing would know that as far as you, right now, are concerned, well you would be dead, and I imagine this would matter to you very greatly. If I move a file from one hard drive to the other, as far as I care, it's the same file. But if the file was sentient, its existence on hard drive A would be over, thus its life would be gone.
Some guy said that because we're all atheists we shouldn't be worried because hey after all we're just molecular patterns, right? This is backwards. If you believe in a soul then don't worry about it (well, do, because souls aren't real) but once you snap the pattern so abruptly, 4 dimensionally, then the pattern is gone, there's no continuity - you're dead.
And no, I'm not the same person I was five/ten years ago. Because I have temporal continuity from that person, no-one died, exactly. But he's gone, I am ultimately a different being.
Edit: Some very simple thought experiments prove this.
As has been suggested - think of yourself getting in a teleporter and being teleported to another destination, except your original isn't destroyed. Do you experience the universe from two places at once? No, the original, you, and your clone now have divergent experiences. The continuation of your clone's experiences are not contingent on the existence of the original, hence, it isn't you.
Another - you get into a teleporter, your original is destroyed, and you are output in two seperate locations. Which is you?