Not directly related, but we (Braintree) recently blogged about credit card expiration dates. Here is a snippet: "If you run a transaction in our gateway and enter a date in the past for the credit card expiration date, you may be surprised to discover that we don't validate it. We run the transaction knowing that the card is expired. Why do we do this? The short answer is that financial institutions will still approve transactions with expired expiration dates."
http://www.braintreepaymentsolutions.com/blog/credit-cards-a...