I'm more for something between real blogs and splogs
Having 100 wordpress blogs with posts rewritten from feeds sounds nice to me. You don't need to update every day. After the blog reach 20 posts once or twice per month is enough. I'm against copying the whole text from the feeds (if the feeds use 1000 other wm's)
Those splogs with 3-10 posts on free blog hosts can be very nice way to get a backlink to your real blog.