The Olympics, while wonderful, are nothing more than entertainment, so the ethical considerations of "should we or should we not do X" are typically pretty much inconsequential. The ramifications of a runner setting a new record are, in the grand scheme of things, pretty much null.
The ramifications of the average human being able to learn more in less time are relatively gigantic. So gigantic, in fact, that I think they dwarf what small social-inequity considerations are raised (if it can really be done for a $90 kit right off the bat, then just wait until economies of scale kick in).
Given that the Olympics is ostensibly rooted in long tradition, I would say no, enhancements should not be allowed.
I'm all for allowing drug use of any kind into professional sports. I think it's silly that we watch rather grotesque caricatures of humans swinging bats or tackling people, then pretend to be shocked and admonish them when we find out they're "cheating" by using chemicals. As if the health risks associated with steroids and HGH somehow outweigh the simple risks of broken bones and mutilated joints that are a direct consequence of pushing a body to its limits and beyond on a daily basis.
They put sprinters in vats of water and ice cubes after running to freeze their muscle so that they perform better, and they put thermometers deep in their butts to check for the exact point until which they can be frozen before they get hypothermia. I think if that's allowed then zapping yourself with 9V is definitely in.
The ramifications of the average human being able to learn more in less time are relatively gigantic. So gigantic, in fact, that I think they dwarf what small social-inequity considerations are raised (if it can really be done for a $90 kit right off the bat, then just wait until economies of scale kick in).