One of the things I’ve been thinking about is the effectiveness of searching in Blogs. Search for a phrase specifically within blogs on Daypop or Blogdex and it shows the link to a page. Problem then is searching for the entry on the page. Since blog pages (especially the index pages) are dynamic, the entry may even have disappeared from the page (into the archives).
The problem is the notion of Search on a Page. This has to change for Blogs — the granularity is a single post, an Entry. That is what the search results should be ferreting out.