A disadvantage of the blog-discussion-format is that there is not a direct link from the paper to the blogs that discuss it.
Nature has a solution.
A recent post on Nascent notes:
We launched a new blogs portal on nature.com earlier this week. It's part of a general overhaul of blogging at NPG which amongst other things involve link backs from articles to the blog posts writing about them (bloggers get traffic, our readers get conversation around papers - works for us both) and improving the blogging experience for users on Network.
Well a partial solution anyway. They are still wedded to their Total Information Awareness approach in that you have to submit your blog and claim it via some registration credentials. In short, pseudonymous bloggers have to tell Nature who they are. So that's kind of stupid and continues their failure to understand the root cause of their inability to spark online discussion of papers.