With this latest update, the hope for help for agricultural products dims further, and it is likely that entire sectors of the agricultural business may be a total loss.
Now, we look from the short term corn crop concern to the question of 'How long will this last?' I can tell you that it will take months to regulate this deficit.
The areas needing most precipitation (on the order of over 15 inches of rain) includes the Southern Plains into portions of the Midwest. This is typical of an El Nino pattern, with a possible expanse eastward and further deterioration of soil conditions.
I am predicting this drought to continue for months to come, into 2013. Considering we are entering an El Nino, I find the Plains and Midwest to be between a rock and a hard place, with El Ninos typically delivering below normal precipitation to the mentioned areas.
If you are a farmer based in the Midwest, I must say that the next 4-8 months (or beyond if the pattern holds) are looking miserable for agricultural crop harvests and/or plantings.