Man, this thread has really kept going! It was the beginning of 2011 when this started! Anyone watch Doomsday Preppers? There are good/bad, realistic/unrealistic aspects to it, and then just some real craziness, but there are a few pointers that anyone could benefit from!
As far as "chicken prep" goes, here is what I'd recommend:
1. Secure the coop and run ASAP, with quarter inch hardware cloth and whatever else it needs. IF things get worse, you'll wish you'd bought that stuff now. Anyone can find materials and scraps these days, but if things got worse, you better believe scraps and extra materials would get used up quickly.
2. If you can, get a rooster for your laying hens and a few reliably broody breeds. Laying hens are great for eggs and even meat, but they don't reproduce (chicks) on their own, and they don't live forever (or even that long, in the big scheme of things). For true sustainability, you'll need that rooster (or 2) to give you new chicks, and the broodies (silkies or whatever breed you want that goes broody) will help you hatch and care for chicks without the need for electricity (heat lamps, brooders, hatchers, etc.).
3. Grow sunflowers and corn for feed. Start a compost pile and farm mealworms! There are easy/cheap ways to feed your chickens in a Depression/Recession/Doomsday/Etc.