Yes, I think the shortages are real. Not because the food isn't available but because of the rising fuel prices driving up the costs of everything else. People are worried and they want to stock their pantries.
A well stocked pantry is an excellent idea, but if the economy is really tanking, we have two options - get down on our knees and repent and cry out to God for mercy or panic and hope the government will save us. (I am sure we all know how well that went over with Katrina.)
Whatever we do, we need to be prepared for a future with very high fuel and grocery prices, as well as the possibility of empty store shelves. I think this means more than just stocking the pantry - it will only last so long. Think gardening, storing seeds, buying livestock if you have land, etc...