Well, I've been trying out Google's new Blog Search. I like it -- of course, maybe that's because if you search for "Web cookie," the first entry in the results list is Tekrati's Blog pointing to my recent report on Web cookies. In contrast, if you look for "Web cookie" in Google's Web search, that same blog entry turns up in position 29 (at least at the moment).
As Charlene Li points out in her blog, rank in Blog Search appears to be a combination of "timing, links, and keyword frequency." Getting the ranking right is something that's going to take everyone awhile to figure out, as the value of an entry to a reader is a combination of the person, the entry content, and its timeliness. Google has grappled with timeliness in its News Search, but the source as a variable is new. For example, let's say President Clinton starts a blog (which he may already have done, for all I know). Initially, before the blog is known, it wouldn't have many inlinks, and its importance may appear to be low. But based on his previous employment history, shouldn't his entries rank a bit higher in value than that of a selectman in Andover, MA, for example? Of course, if he writes boring stuff, the rank will eventually go down; however, I'm thinking he should get some initial rank boost based on his experience outside of the online world.
Or, maybe he shouldn't, as the blog world is a free market of ideas, and no one should get a subsidy for aura. In any case, blog search and results ranking is in its early stages, and it will be interesting to watch how it evolves.