If you come here to see what's on, I'd also recommend having a look over at matt reed's blog, for Matt always seems up to date with what's going on in the world of organics....
there today, I learned that more research has come out suggesting that organic is more nutritious....like Matt, I'm a bit skeptical about this sort of research, though I have written the odd article in this vein before myself....
when I did write one for the Irish Times in this style, I got some positive feedback from various places. Two valid criticisms, or additions to the debate, were the following:

1: essentially it's v difficult to really compare the products - you have to take into account so many issues (distance, age of product, size of farm, crop rotation used, and some of these aren't strictly comparable between conventional and organic)
2: Science should also look at the subjective effect of both conventional and organic over a period of time on an individual, not just 'product x vs product y'.

As a further addition, you should then really start to look at how the products are used differently by consumers in a variety of settings, e.g. the home (Lockie et al 2002 quotes consumers who used to let conventional veg go off at the back of the press, but wouldn't dream of doing this to their organic veg...why does this happen and what does it mean?)

And then we have the age old problem of organic embedded into a world of conventional distribution, trying to maintain it's own certs and standards, which add to organic food miles and thus to the age of organic products, while only being a 4ish% of food production accross the EU...how would organic and conventional compare nutritionally if they each had all the inputs and processes necessary within each, or more importantly comparable reach of their respective places of production?