Here's what
the Microsoft Websitehas to say about the discontinuation:
This retirement will not affect software already installed. Current users may continue to use Streets & Trips to plan their travel adventures and will have online support until July 14, 2015. Streets & Trips 2013 will be available for purchase until December 31, 2014.
So... If you check for an update just prior to July 14 of next year, you should get the latest data they have available. That should be good for at least another year.
Meanwhile, does anyone have anything nice to say about Rand-McNally's RV GPS? That's the one I'm thinking of getting.