Recently, I reposted a piece from a previous year and was asked in the comments why I reposted my question if it was answered in the comments.
Because most of the stuff that is posted here is relevant to the פרשה, it makes sense to bring the issues up all over again in following years (especially advisories.) However, there is often discussion in the comments that is crucial to the topic at hand. The problem is that when you view the blog on the main page, the comments are not shown unless you click on the link. And I also believe there is something to be said about maintaining the original integrity of the question-answer process.
This week happens to feature many reposts. What I have begun to do is to take important comments from previous years and paste them in to the actual post and remove them from the comments. That way, they will show up (with proper attribution, as well) on the post.