As a blog post:

http://michaelnielsen.org/blog/open-access-a-short-summary/

I've now edited the header of the HN submission to point to this URL.

Thanks for the suggestion --- I should probably have done that initially. My thinking was that I didn't want to put it on my blog, since it's meant specificially for HN. But with a little framing, that issue takes care of itself. And, as you say, the links work a lot better in a blog post.