Looking at the comments here, am I alone in being completely unaware of famous users here? While browsing HN I pay zero attention to the users and simply look at the content or comments.

I think I am like you. I recognize almost no one. It gives me this weird feeling that every comment comes from a unique person, and that the number of people commenting is approximately infinite. Which I understand rationally to be wrong, but still.

Concur, it feels lonely out in space. Do you think that if the username were subtly emphasized (bold, or on its own line) we would notice it more?

If this was a problem, the solution would be to allow avatars, and give a unique one (like gravatar) to users who don't set an avatar themselves.

If anyone wants a quick, nice pop-up on mouse-over, there is 'Refinded Hacker News' plugin for Chrome and FF: https://github.com/plibither8/refined-hacker-news