Is Blog Search Different?

Alerted by Jeff and Iadh, I recently read What Should Blog Search Look Like?, a position paper by Marti Hearst, Matt Hurst, and Sue Dumais. For those readers unfamiliar with this triumvirate, I suggest you take some time to read their work, as they are heavyweights in some of the areas most often covered by this blog.

The position paper suggests focusing on 3 three kinds of search tasks:

1. Find out what are people thinking or feeling about X over time.
2. Find good blogs/authors to read.
3. Find useful information that was published in blogs sometime in the past.

The authors generally recommend the use of faceted navigation interfaces--something I'd hope would be uncontroversial by now for search in general.

But I'm more struck by their criticism that existing blog search engines fail to leverage the special properties of blog data, and that their discussion, based on work by Mishne and de Rijke, that blog search queries differ substantially from web search queries. I don't doubt the data they've collected, but I'm curious if their results account for the rapid proliferation and mainstreaming of blogs. The lines between blogs, news articles, and informational web pages seem increasingly blurred.

So I'd like to turn the question around: what should blog search look like that is not applicable to search in general?