You need to make sure you didn't give away something specifically named in your will for a certain heir. You set up a business of your own. Consider whether your business is a sole proprietorship, partnership or corporation, changes are probably in order. You change your life insurance program. You no longer need the same kinds of protection.
Tax laws change.
Federal laws changing may make a pre-existing will less effective. State laws of descent and distribution change. It's a good idea to check with your attorney to have a will check up.