This is an incorrect explanation, and you can thank the media for spinning things out of proportion. What the experiment actually yields -- and this is indeed profound -- is that there is an organism inhabiting Earth that is capable of incorporating the compound arsenate into its nucleotides instead of the compound phosphate. However, this was only possible after giving it arsenate in a phosphate/arsenate mixture. Pure arsenate consumption occurred only after phosphate was removed from the mixture. So, what you actually have here is an organism that prefers arsenate as its energy source, but will take up phosphate in the form of ATP just fine, too.