One option is that a site can drop back to a session cookie if permanent cookies seem to be disabled. If a site really does require permanent cookies, then it should say so with a clearly worded error page. Having a Web site do flaky things does no one any good. Microsoft and Netscape can help out here also. A browser option like this would mean that Web sites still get to use cookies, but they can't track me over the long haul.
Cookies are now part of the fabric of the Web.
It is unlikely that they are going away anytime soon. I think a great solution to the tracking problem of cookies is to keep them on a short leash. Just because some Web sites want to have their cookies in my computer until the year 2038 doesn't mean that I want them to stay around that long. I doubt very seriously that either myself or my computer will still be on the Internet in year 2038. A great compromise then is to have an expiration date of only a day or two for most cookies.