While I am sympathetic to ideas of wanting to "back" btc with something, it is impossible to do without some degree of centralization which is unacceptable. For instance, if your proposal were to be adopted it would effectively mean that miners have to pay for your backing plan. So essentially miners are supposed to pay into a "when sh*t hits the fan" fund that will benefit everyone at their expense.

Furthermore, your plan gives an unfair advantage to Mt Gox. Why should they benefit from the guaranteed volume as a result of processing the "back btc auction"? Can we even trust Mt Gox since they came out the other day saying they will hand over details of peaceful people who freely exchanged goods to the thugs who call themselves the DEA.

Who is going to take the role of uncle sam and redistribute wealth from miners to Mt Gox & "society"?

I think this post is a great insight into how socialism begins. The reason you are able to make such a proposal is that you don't have to pay for it. Otherwise you'd just "back" btc yourself at your price with your money.