That was the conclusion some friends and I came to on the topic, RedSox. We said that exploration would still be valuable. Eventually, the death of the earth will spell the death of virtual worlds hosted there. Exploration is mandatory for human survival. It is an interesting thought experiment.

To get back on topic, I suppose this technology is a pretty far off. It may be possible from a technical standpoint in a decade, but handling particles isn't exactly easy. Look at the process for the production of antimatter. It is neither simple, nor cheap. Even if they are self contained in a sort of "atomic ink cartridge", I doubt many manufacturers will be in the market for packaging protons, neutrons, and electrons. I would file atomic 3d printing under "very distant, but nearly possible".

I really hope to be eating these words in ten years, but I doubt I will.