Make the comments wider and the stories on the front page a little easier to tell apart.
1) The comments are way too narrow. Look at a place like reddit. I think of slashdot as the more tech-oriented reddit where the empathizes is on commenting and reading the comments. Due to this, many people post long comments, having them all smashed just makes it harder to read. I don't come to Slashdot to read the articles, I come here to read the comments.
2) Right now on the front page it's difficult to glance and see each story because everything is the same color. Take a look at the current page - each story has a bright green line which makes them very easy to quickly scan and figure out which one you want to read.