Really, the entire issue is a non-problem. Hardly anyone has these kinds of problems that can't be fixed through either rearanging your site, using robots or htaccess files. And most sites don't even have the need for even any of that. Anyone outside that box, well, we're looking at one in a million. It's a hammer looking for a nail.
Nevertheless, I'm not disputing the technical aspect of it, anymore than I dispute the technical aspect of the nofollow tag. I am disputing that this is not what webmasters want to be doing long term. It's good for the SE's at the potential long term expense of us. We're (well, not me - it's youse guys) are building the next MS monopoly with this kind of behavior.
All that being said, I somehow doubt that this is actually going to help anyone's ranking noticeably, or make enough of a difference that couldn't be 'fixed' by some more backlinks. There's no way this is a panacea for helping people to rank. And if it's not, what the heck, you need more work to do or something :)?