A new USDA proposal would change the rules for hops used in organic beer. The actual rules proposal is at the USDA's site.
The change would add hops to the National List which would allow non-organic hops to be used in certified organic products if the organic version is not "commercially available". According to the rules, the commercial availability is determined by an "accredited certifying agent" as follows:
The ability to obtain a production input in an appropriate form, quality, or quantity to fulfill an essential function in a system of organic production or handling, as determined by the certifying agent in the course of reviewing the organic plan.
The critics of this part of the rule call it the "Budweiser exemption" since it was allegedly lobbied for by the beer manufacturer. Critics also charge that "commercially available" is industry speak for expensive so although organic varieties may be available, the high cost does not allow it to be commercially available.
Lakefront Brewery's president commented on the proposed rule to argue that organic beer should use organic hops with no substitutions. You can read this and other info. on this topic at Beer Activist.