straight from the FAQ
Q: What happens when my subscription expires? Will the programs I’ve received still work?A: Yes. When you purchase, you receive everything currently available on the Object Desktop Network as well as free updates for one year. Once your subscription has expired, you have the option of renewing for additional years for $34.95. If you choose not to renew, you keep everything released prior to the subscription expiration.
Think of it like you would a magazine subscription. If you let your Newsweek subscription lapse, you can still read all the old issues (you just will not get any new ones).