This is one of the things I am most excited to try out! I hate having my phone out when I am in an urban area I don't know, so the ability to keep my phone in my pocket, and my watch hidden, and still get ongoing directions? That's a huge draw for me, so I really hope they keep the left/right directions as separate.
However, I'm kind of hoping --don't shoot me-- that you can integrate it with Google maps, as well. I'm not very fond of Google, but their location reports for businesses is better than Apple's for my country. I just opened Maps on my phone and scrolled around the city center, and I can spot a few big mistakes almost immediately.