Very nice! As others said, as if I need an easier way to be distracted by HN. ;) I love that you made reading comments so easy -- that's usually what interests me more than the actual articles.
One suggestion: When you're reading the comments, it would be nice to have a way of opening the full article. I usually read the HN comments on an article before clicking over to the article itself and unfortunately your app has no way of opening the article from the comments view.