Farm Policy has the text of the Brown/Thune/Lugar/Durbin bill establishing the Aggregrate Risk and Revenue Management Program. Given the prominence of the co-sponsors, it's got to be taken seriously. See this for a diagram of the calculations.
I'm too far away from current law to comment reliably, but I didn't see the commodity-specific determination as all that specific in the bill's language. I do wonder about WTO compliance, because the program is tied to planted acreage and seems to discourage switching to new crops. That was a prime selling point for "Freedom to Farm", which became the direct payment program.
In terms of administration, I surely hope FSA and RMA have merged into one entity, because I don't see how it can be effectively administered otherwise. Assuming FSA writes the checks, they need the RMA APH and insurance premium amounts, plus the planted acreage and the actual production. I shudder at the complexities. I also wonder how MIDAS would plan to handle it.