They're not updates, they're beta standalones of the next versions of FX and VCPro, a framework for features and new tools in development. You can save from them before they time-expire, but they're not add-ons or upgrades for existing commercial versions of FX8 or VCP. They might be missing some of the features of the retail versions, they might be less stable in comparison, or they might be a brilliant Great Leap Forward, but you don't have guarantee of either. They'll provide a code base for the next version of Shark LT, but they won't overwrite or connect to your current one, except through file transfer. You might as well sign up to use them, they're free for now and you might find the new or additional features useful.