Oh good - yet another format battle brewing in the geekosphere. And now that I'm feeling better, I can't help but jump in :)
Case in point: during the first year of FeedDemon's development, I heard countless users complain that a certain feed wouldn't display correctly, and much of the time the problem was that the feed contained incorrectly encoded HTML tags. Developers of several other RSS readers reported the same thing. Bottom line: the imprecise RSS specification resulted in a lot of guess work, which complicated things for developers, end users and feed producers.
The solution? We clarified the RSS spec. While problems with entity-encoded HTML haven't disappeared completely, in my experience they're far less common than they used to be (and when they do occur, we now have examples to point to).
And that's all that's needed here, too. Clarify the OPML spec, and we can skip another prolonged format battle. Dave, once I've recuperated, I'll gladly help polish the spec, and can assist in creating example OPML files for developers to test with.