Wytheville to the Rescue?
I decided to try a little experiment with my Bloglines subscriptions. I've taken all the blogs that weren't giving me good feeds or any feeds at all, and (re)subscribed to them via the Wytheville Community College (WCC) RSSify connection. And all blogs seem to have WCC feeds that didn't show up when I just pasted in the URL itself. So I'm back up to being able to access all 225 blogs on my blogroll via Bloglines (with asterisks on 52 of them, or 23%). If you're on Bloglines, instead of putting in the URL of the blog into the "Subscribe by Entering URL" box, put in "http://www.wcc.vccs.edu/services/rssify/rssify.php?url=[the URL of the blog to which you want to subscribe]" and see if it doesn't come up for you as well.
Now, I'm still not really sure how all this works, but as best I've been able to figure out here's the catch: if you subscribe to someone's blog this way and the blogger hasn't set themselves up for a feed, the connection can't actually notify Bloglines correctly of new blog entries/posts (which Bloglines calls "items"); if you hit "Preview" when you subscribe, you'll get the message "There are no items available for this blog. This could be because the blog has not been indexed yet, or it could be because Bloglines was unable to properly parse the blog." So you'll probably have to note that on your subscription list; I'm using asterisks there the way I've been doing on my sidebar.