I'll cut to the chase with the suggestions. Digg this if you like it.
1. Make comments appear in real-time - When you Digg an article, you can see the Digg number increment in real-time. Do the same for new comments. Why? Because of stories have a large number of comments, and refreshing the page every time to post a new comment or check for newly posted comments by others takes some time. Refreshing it over and over can get annoying for these more largely commented articles.
2. Comment Pagination - This branches off the same idea as the previous suggestion, refreshing pages with many comments takes a while, so why not have pages of comments? The number of comments displayed can be set in the user profile, like 10, 20, 50, etc.
That is all.