As you probably already know, the Samsung Galaxy Gear was fairly limited in its feature-set initially, but Samsung has added more and more functionality to the smartwatch over the last few months.
Looks like the Galaxy Gear is getting voice guided navigation through their headphones. We learned, however, that the majority would just visually remember the route to take, immediately close the app to save battery life, and put their smartphone back into their pocket. From time to time, they would reopen the navigation to check whether they're still on the right route.
With the Android SDK, it was easy for Symphony Teleca to develop TurnByTurn, an app with which you can plan your routes on your Samsung Galaxy and then synchronize them with your Samsung Galaxy Gear. The smart watch will then take over all the navigation instructions and alert you visually and audibly about upcoming turns.