Google's Terms of Service for Google Maps don't allow 3rd parties to provide a simple way to transfer driving directions to GPS units. Therefore, I can't use TakItWithMe to easily transfer my Google Maps directions to my Garmin Zumo 550.
So, that begs the question... Why not? What is the big issue?
Also, the Garmin tools (Bobcat and Mapsource) for creating routes totally blows compared with Google Maps. So if those tools were better, this would be less of a concern.