1) It would be integrated with other Web search. (People don't want to have to search twice)
2) No moving knobs to toggle between new posts and important Web pages. (The "advanced search" options on the engines today get minimal use.)
3) Posts from certain blogs, either highly trafficked or ranked by the individual user, would jump toward the top of the search results.
Fletcher, whose Bloglines provides search, says that none of the current systems, including his own, produces good results. Why was I talking to him about search? A few months ago, he vowed that Bloglines would come up with a world-class search engine by summer. He still says it's coming but won't say when. But now, at least, judging from his vision of ideal blog search, we know what to look for.