Apparently with Oprah's "blessing" of this product, there was an overwhelming response to the coupon redemption, and KFC has suspended their accepting of it. However, if you had a chance to print it out, not to worry, they will still honor it, but in the form of a raincheck. All you have to do is take your coupon into a KFC, fill out a small form & turn it back in, with your coupons attached. Your rain check will be for the meal + a drink, which the coupon didn't include. You can go here for more details. Each household is able to redeem 4 coupons for rain checks. Reportedly, there are still some KFC locations honoring the coupon, so you might just get surprised when you go in for a rain check & are still able to redeem your coupon.
**EDIT: Amiyrah over at 4 Hats and Frugal has been so kind as to post a PDF/scanned version of the form you must fill out and attach your coupons to in order to receive the raincheck. It can be found here.