Mt.Gox could solve its nuisance micro-order problem with much lower fees [than E*Trade]. And they would rid themselves of the
front-running suspicion as well.
Sounds like a solid business plan for a competitor...
Mt.Gox has captured a natural monopoly. Or, to explain it with a saying, translated from lower German, "The devil shits by the biggest heap."
Competition is possible, but the competitor would face a very steep up-hill struggle for a long while. Mt.Gox could lower their fees to much lower rates and still make money.
That said, I would greatly appreciate more competition.
You are quite right that the fees are exorbitant now. I expect a serious competitor to gox to emerge within the next year probably in the US now that it is essentially legal. It will take big money to dethrone them, which is fine because big money is being tossed at this at the moment anyway.