Blogs, links, and canonical URLs

If on different articles on a blog, we include links to the same page, is this a total waste of time?

I think of it like this:

If the canonical URL for each article is the name of the article, then each article is a different page. So the additional links might be a little worthwhile.

If the canonical URL for articles is either by tag, month, or the front page, then many of these articles on the same topic are a waste of time.

How does blogger and wordpress treat this? Is it a setting that we have control over?
Matt Cutts, I just watched your video on canonical URLS, you didn't mention how blogs fit into this....