Great question with a couple answers.
Interruption? -- in Summer 2009, Ohio had a full 6 year's worth of corn crops from 2003 - 2008 inclusive in storage silos already and put more in storage. Quite a few gasoline stations in Central Ohio are selling corn-enhanced or -based fuels for 50 to 80 cents a gallon less than gasoline and we still ahve all this corn in storage. Too much corn lying around.
A documentary a year ago on a cable network showed that in biofuel production in the processing factory shown, the ears of corn (food aprt) were not used, only the stalks and the rejected corn ears not used for human and animal consumption. I don't think it's an interruption of food at all.
At the same time, 2008 discoveries of enough oil at New Town ND on the native reservation, where about 40 more oil wells are being placed in 2010, are estimated to be able to provide all the oil/fuel needs of all of North Ameica are at least one century, some scientists say 200 years. This makes corn interruption a moot point.