That's right. They're here. Now you can comment directly on individual lines in the Diff attached to any Pull Request.
These things are smart. They keep their proper position, even after pushing additional changes to the same file.
Diff comment threads are also interleaved chronologically into the Discussion view along with a small diff excerpt for context. Great for coming up to speed on the evolution of a branch over time.
Leaving line comments is easy. Hover left of the line that you hate and hit the bubble.
Want to know more about how people are using Pull Requests? Check out our Futuristic Code Review feature page.