That's the big downside to using Garmin, they're very tight-fisted with map updates (don't know if magellan or their other compeditors do it any different, though). In almost all cases you have to pay for updated maps. The only exception is if you bought some of the mapping software after a later version was released, then you are entitled to a free update.
They are, however, very good with firmware updates to the actual GPS units themselves, and to the map viewer/routing programs (i.e., MapSource mentioned above). These seem to come out in a steady stream to fix issues and to expand functionality, and are free.
