The State of California is scheduled to vote on a forthcoming ballot initiative this November, which would require labeling of genetically engineered products that are sold in the State of California. (Ballot detail roundup here.)
In addition, if Proposition 37, "The California Right to Know Genetically Engineered Food Act," passes, food with any genetically engineered ingredients would be unable to be branded as "natural," "naturally made", "naturally grown", "all natural" or "any words of similar import that would have any tendency to mislead any consumer."
Also, companies wouldn't be able to label food other than a raw agricultural commodity as natural. For example, food that has been "subject to processing such as canning, smoking, pressing, cooking, freezing, dehydration, fermentation or milling" and is not otherwise exempted, may not be labeled to imply that it is "natural."
Exemptions include medical food, food prepared for immediate human consumption and food certified as organic.