I was only able to see recent posts/comments. I'm not sure if the API supports it (haven't looked) but would be nice to see older posts/comments as well, and agree with others about an RSS feed being a good idea.

In addition, an aggregate RSS feed of higher ranked HN'ers would be neat.

And clicking on the following without specifying a user to follow first ("logging in") doesn't work: http://hackerfollow.com/?filter=devmonk but as soon as a specify a user ("log in") it works. It should just work if it is essentially public, imo.