Just to throw my two cents in:
The 'yuppies' that buy organic food believing it to be more nutritious have clearly always been ill-informed. This shouldn't be a surprise, should food grow better with or without pesticides / additives etc.? Probably it would grow better with human and scientific intervention.
That is almost beside the point.
Also the issue of 'organic' food tasting better must be purely 'in the head'. Why would it taste better? This doesn't really make sense either? Does it?
Fresh food grown locally, yes I can see this.
No, I propose, as briefly alluded to by others, that the overwhelming benefit of organic food is to other things. If you were to walk round a farm producing crops truly organically, the difference in biodiversity is huge. i.e. the strips of wild planting at the edges of the fields which are necessary such that birds can live there to eat pests etc.
Compare that to the comparitive 'desert' of the highly efficient modern farm, square mile after square mile of wheat and nothing else.
It is a shame as far as I am concerned that this never gets brought up for the following reason:
'It costs'
'I don't benefit'
Hence they have to sell organic food on lies, as no-one gives a flying f*ck about the number and health of various species of birds living in Norfolk, and other such important things.
Also, I personally disagree with the blanket statement that Organic farming is not sustainable. I do not believe this has been tested sufficiently to prove either way.