Had this exact situation a couple of years back, at Copenhagen I think.

Card expired between booking and the day of the flight (good few months gap), and to my suprise the check in agent insisted I should have kept the old card and brought it with me. Managed to sort it another way of course, and in fact that's the only flight I've EVER been asked to present my credit card at check in.

Booking a flight last week though I did notice it says in the small print you need to have the card used to book to present at check in.