You've heard about this for weeks now, and if you've opened Storybook Creator, you've probably been prompted to update. This is important to do, because it will allow you to create projects to be printed at the Panstoria Print Shop, which offers some fun new items. (You can get an idea about what's offered in my post A First Glance at the Panstoria Print Shop.)
If you've already done it, great! You're all set.
If you haven't done it yet, here's a quick video to walk you through the process.