The price of Ag commodities (all commodities--grains, oilseeds, pork, beef) is highly elastic. It can change 20% overnight when there is uncertainty.
If ethanol creates a demand for more corn acres, uncertainty is in the house. Then you throw in the increasing demand in the world market and you have a situation that demands attention.
Farming those less productive pasturelands will be a bust in a couple of years, I think, as these markets WILL correct. A big move up in price is never permanent. The farmer in Illinois making 250 bu will survive the downturn. The farmer in SD making 80 bu corn won't survive.
Livestock producers are risking a lot right now. Hog and Cattle prices have not participated in this party. We are gambling that our prices will catch up to grains and oilseeds, and we are shelling out for high priced fertilizer, herbicides, minerals and etc. while we wait.
It takes time to shrink the cowherd, but it will happen. It is happening, about 1 or 2% /yr. I expect that will only accelerate. Folks without jobs aren't going to buy many steaks. Pushing more beef at a higher price into a sluggish market is not a job for the faint-hearted.
Ok, rant over.