Nokia just announced that the turn-by-turn navigation addons to their (underwhelming) gps software, Ovi Maps, will now be offered free of charge, completely undercutting TomTom and friends. They can do this thanks to the recent acquisition of Navteq, the top map-making company in the world (which is still selling map data to competitors at a hefty price, by the way, including Google); and they have to do it, because Google is doing it as well on Android and iPhone.
If Nokia can really deliver (i.e. actually improve Ovi Maps, which is quite frankly not as good as commercial competitors yet), 2010 will be remembered as the year that GPS devices became obsolete, like it happened to PDAs about three years ago. TomTom shareholders better run for the hills.