Apple Maps have always had turn-by-turn walking directions, provided you had your iPhone in your hand. Now its new Watch will not only provide high-quality maps right there on your arm, it will also give you an haptic nudge when you need to turn right.
Using the Watch (do we call it "The Watch?"), you'll be able to summon directions and navigation using either the "taptic" touchscreen or Siri. You can zoom in to see the route, but that watch screen is still pretty small. So once your walking route is set, the Watch will know where you are, and vibrate when it's time to turn -- one kind of buzz for left, a different one for right.
One problem for people using their Watches to get around town: Apple's Maps still don't offer transit directions, instead they send you off to Google Maps. The best possible combination of any non-car directions would not only tell you to walk left or right but also direct you to a bus stop or train station when needed. So either Google Maps will need to incorporate the same haptic feedback for the Watch, or Apple needs to add some transit directions, stat. Also how about the same thing for biking directions?