That's an excellent question and we are happy to provide a response.
First, we actually just posted some info on labeling and why products from GMOs are not currently labeled - here's a link to that info. http://gmoanswers.com/ask/why-are-products-containing-gmo-plants-not-clearly-labeled-grocery-store
From the Post: “…. questions about labeling are great questions. We are often accused of being against labeling. We are not. We want consumers to know about GMOs and support the right of consumers to choose food that is healthy and nutritious. What we cannot support however is a label that conveys to consumers that foods made from the farmers’ crops grown with our seeds are less safe, less nutritious or somehow different from conventional or organic food. We believe a government requirement to label a GMO food would do just this. Hundreds of independent studies have confirmed the safety of GMOs (available here) and regulatory authorities around the world agree.” When it comes to hiding, it's actually quite the opposite. There's no need to label a product when there's nothing to hide or define as different. In other words, no scientific justification to provide a label for GMOs."
Here's more information on the topic. http://www.aaas.org/news/releases/2012/media/AAAS_GM_statement.pdf