If you have Windows automatic updating or are running Vista, you should be covered. If not, you may want to visit the relevant Microsoft support page to update. Apple also has update information here.
Our real concern here is (what else?) voting machines. Under the old schedule, the Fall Back happened the last weekend in October. Now it is the first weekend in November, which means that, two years out of seven, the changeover will happen after Election Day, not before. And of course, since voting machines are not (supposed to be) connected to the Internet, automatic updates don't apply. Fortunately this won't happen until 2010, which should give our registrars and their oh-so-reliable vendors time to fix things.