You can get forum posts if the forum provides RSS feeds. I was just giving an example of ways you could use a scraper to build your blogs up.
You can also use the scraper for article websites, just not enzine and goarticles because they have bot protection, and I have no clue how any of the other scripts get around this.
You can use the scraper to turn partial rss feeds into full, but not every blog associated with a google blog search, because each blog will have its own template system that you have to figure out in order to scrape the content,
so if you have a feed with content from 10 different sources, the sources will be too varied to have one scraping pattern work for them all.
Like WP Robot, you can create google alert feeds and have partial content with links to full articles show. I do this with
http://www.autobloggn.com.