I have to agree with hairypizza in the sense that this seems to be self-negating. I want to say up front that I'm not exactly bagging the concept, but more scrutinizing it's usefulness...
Power conservation should be done on a more subconsious level by everyone all of the time. Given the fact that this won't happen since the majority of energy consumers aren't really even aware of what their appliances actually use, they don't know which ones are best to turn off during peak times.
A real world example of this hit me like a brick when I was setting up a 47" LCD TV last year... It draws almost 400 watts - 50 more than the 27" Tube version it replaced. I would have never guessed, and I've been dinking with electronics for 25+ years and know the key differences in the technologies!
Now imagine that most consumers only see the "energy star" and leave it pretty much at that in their minds, assuming that it is helping to "save the planet"... Follow me on this seemingly ridiculous example...
If the entire world were made up of people of the kind found on this forum, this would be an EXCELLENT idea, since intelligence could prevail.
Since this isn't the case, it seems to me all it will do is peak people's interest, since "green" is such a buzz word these days, and have the effect of "turn on the computer - I want to see if I can zap my coffee in the microwave".
The result would be, in the time it would take to boot the machine, get on the site, and find out the current state, the computer will have drawn a few times what the microwave would have to warm the coffee, all because of ignorance. They know that 1000W means the microwave uses a lot of power, but most people don't know that between the computer and monitor, they could be approaching 500W. If your intent is to zap your coffee for 30 seconds, you'd have to be able to boot up your machine, get your info, and shut it back down in under a minute to see any benefits. Not likely.
Add that to the idea that firing up the computer is "wasted energy" (doesn't help heat the coffee), and you're out that much more!
Just my two cents...
Steve