Nope, your dry beans are good pretty much forever, as long as bugs don't get to them. That said, it's true that the longer they've laid around, the longer they will take to cook up soft.
(Can I say how much I love dry beans, especially since I'm poor? They are infinitely forgiving, nutritious, filling, varied and tasty, and amazingly easy to cook. If I had my way, every state/city/local agency that helps poor people would give everyone, at a minimum, instructions on how to use dry beans!)