Very interesting insight into what the future may hold for grain farming.  As you (Pofarmer) pointed out we have already seen tremendous consolidation in the hog business.  Poultry is already there.  The number of smaller beef herds is dwindling along with dairies. 

It all boils down to economies of scale.  Years ago farming was like many other small businesses.  They were operated by family with the sole purpose of providing an income sufficient to support a family at a modest level.  Remember the small Mom and Pop stores that were in every town?  Drug stores, hardware stores, gas stations, restaurants, car dealers, banks, etc were all locally owned and consisted of one location.

Now look where we are today.  National drug store chains, hardware stores gone due to Lowe's and Home Depot and the one chain that has contributed to the demise of more small businesses and towns in American than any to other......Walmart.  

When us older folks look back at the number of farms in a community when we were young vs what we have today we see a landscape that is totally different than what it was 40 or more years ago.  Bigger equipment and  economies of scale will insure that this trend continues. 

The one thing that has been a limiting factor to all of this has been control of the land.  If we were in a market place where all farm land was owned by absentee owners who had no other goal than to maximize return on investment then we would see greater consolidation in grain. Landowners who still farm the land themselves or rent their land based on criteria other than the "high bidder" will continue to slow down the consolidation process.  

I am afraid that Pofarmer is pretty much correct about what the future holds.  It is not a matter of if, it is a matter of how long it will take.