You kind of have to stare at it, and think and poke around to see all the interconnections. This is pretty fully-baked stuff.
Hidden away is the Accept header that allows you to request the OPML instead of the HTML. And then you're off to the races. (Because you get all the structure and data along with the text.)
If Google had a similar feature, I wouldn't have to link to Chris's post, I could include it.
That's what we all should be aiming for. Structures that seamlessly bridge systems, so we have real interop. Then we get to the next level, and have some fun before the next opportunities start coming into focus. The blogging silos that Google, Facebook and others are developing are not the answer.
Like, we didn't know that political blogging would be big when there were just a handful of blogs. That kind of observation.
Intuitively I think this tool gives new purpose to academics, researchers, librarians, programmers. After that, I don't know. Lawyers maybe.
BTW, Amazon's Route 53 was the missing piece for a long time. I needed a way to program DNS, and they finally delivered more or less exactly what i was looking for, at least to get started.