Correct me if I am wrong but this restriction is only based on the restriction in funding for FY 2012. After that it may not apply. I dont know if this will need to be renewed yearly. Also you need to read the fine details for the restriction. Here is what I found with a google search.
SEC. 541. None of the funds made available by this Act may be used to pay the salaries or expenses of personnel to deny, or fail to act on, an application for the importation of any model of shotgun if–
(1) all other requirements of law with respect to the proposed importation are met; and
(2) no application for the importation of such model of shotgun, in the same configuration, had been denied by the Attorney General prior to January 1, 2011, on the basis that the shotgun was not particularly suitable for or readily adaptable to sporting purposes
it is my understanding that if a shotgun was denied importation prior to Jan 1, 2011 it will still not be allowed to imported now regardless of sporting status. So this probably means they cant ban a Saiga S12 or Benelli M4 as they have been previously approved. However, they will be only be able to be imported in the configuration that was previously approved. I dont think it means you can add whatever you want to those models and import freely as 922r still applies. The way around this would be to have new models approved with all the features already installed but I dont think this is going to happen.