I am not sure why people are getting excited over share your OPML; this seems like yet another vanity/popularity service that will soon attract spammers and other bottom dwellers much like Google Page Rank did. It is definitely attracting the attention of those who see it as a marketing tool (sorry, I mentioned bottom dwellers already).
I can get excited about someone that truly implements a relevance system for my OPML or RSS reading habits. I define relevance as presenting me with things that I want to read based on what I read, not on someone else’s notion of popularity. I really, really don’t care what is popular, I do care about what is important to me — it’s that simple. And I can’t imagine that I am alone in that feeling. Sadly, only the dearly departed Searchfox has come the closest to implementing this.