I'd like to know when there's a new reply to a comment I made in an article, without having to click my username, then comments. So basically a notifications icon/link at the top right.
I'd also like to be able to follow users that I think are interesting, to be able to see their posts/comments. But that would be a much bigger change, and is closer to a Twitter-style design. I wouldn't want this to be the default view, but it would be really interesting as a link on the top left.