Basically, I think there are benefits to local food. And I don't think the problems with local food mean we shouldn't change anything about our food system. But we have to acknowledge that the locavore thing isn't perfect, and maybe isn't as sustainable as we'd like it to be. That's why I like this Grist interview with Pierre Desrochers, a University of Toronto geography professor and author of The Locavore’s Dilemma: In Praise of the 10,000-Mile Diet. Desrochers talks about some of the problems he sees with the sustainability of local eating and explains the nuance of his argument. It's not "local eating" vs. "change absolutely nothing, hooray for Monsanto!" And that's what makes it interesting, and important.
An article that is worth a read about our assumptions in buying local.