Blogrolls have been around for a long time. Many people regard them as a standard feature on any blog. I tend to agree with that point of view. Generally, I find blogrolls useful and they give me an extra insight into the mind of the blogger by showing me his or her favorite links. However, more and more blogs are choosing not to display a blogroll. Probably the main reason for this decision is the difficulty in maintaining a long list of links and the politics that may arise as decisions have to be made about which to add and which to remove. There is also the SEO issue I mentioned previously.
As an alternative (or even in addition) to a blogroll, some bloggers now include headlines from other blogs using the RSS feeds from those blogs. Usually they only do this for a handful of their most favorite blogs, maybe no more...