Seriously, though, there's no way New York City itself could be evacuated without something on the scale of Dunkirk.

Actually, it would be more than 20 times the size of Dunkirk. And that took 9 days. Hopefully there won't be anyone shooting at us, though, if it comes to that.

Contrary to what some have speculated, this is not just science by press conference. There is an actual paper out today in Science magazine (subscription only, but a summary is here). It is speculative, but not of the "arsenic life" or "bacteria in a Mars meteorite" variety.

in short - go and look at a breakdown of resource usage by task, and compare the best plausible or cutting-edge now tech in 20 years, as it could be implemented.
There are _huge_ savings to be made.

That's true, and we will no doubt end up using many of these efficiencies. But in the long run, history shows that as we run out of a resource and find a more efficient way to provide the benefits we had gotten from it, our overall increase in consumption swamps those efficiency increases. We were using whale oil at an unsustainable rate in the 19th century, luckily we found a petroleum alternative to allow our standard of living to continue to increase, but our per capita consumption of petro oil now is far larger than it ever was for whale oil. As is our overall energy consumption, and just about any broader measure of consumption.

I'm not saying we couldn't do it, I'm just saying that (apart from short term deviations brought on by shocks like the 1970s oil crisis, wars or depressions), we have never shown that we will choose to do so.

Might it have something to do with every component being built by the lowest bidder because funding keeps getting cut anytime someone at NASA blinks?

Or the fact that major components have to be built in every state with a powerful Senator?

There is literally no device out there that will run XBMC and Netflix at the same time.

Not "literally" true, a Mac mini would do both just fine. I assume you meant, "for less than $699."