WordPress 2.7 introduced a new feature that better manages multiple numerous comments on a post. They created multiple pages to delineate the comments. Below is an example:
However there is a problem with this, Google will look at this as multiple pages with duplicate content. And as we talked about here, that is behaviour that can get you penalized.
However there is a plugin that will put an extract on each of the subsequent comment pages. “It is in the repository under SEO for paged comments”.