I just ran into an article that nicely sums up why I think the "Certified Organic" label isn't worth the paper it's printed on. Over on MSNBC there's an article about the continuing relaxation of what is allowed under the Organic program. I have long held that (for example) Cattle raised in an organic feedlot are not on the whole entirely different than those raised on a non-organic feedlot.
The real problem is marketing and perception. Because the label gets a premium in the marketplace, more producers (agribusiness) push to get their current products and practices "blessed" by the program. The public (folks I talk to) largely have a false image of happy animals trotting through green pastures. They think that CO veggies are safer. The CO label does not, in any way shape or form, guarantee this. You cannot even be sure that the banned substances have not been used. With the markup for CO produce, using banned substances is a gamble that some producers are willing to make.
For the small, open system, "all natural" producer....? Organic certification is often too expensive to bother with.
If you want to buy organic, by all means. I don't think it'll hurt anything other than your wallet. Better yet, hit the farmers markets and talk to your grocery managers and find out who is producing your food and how they do it.