I loved the article, but more wanted to comment on Ready2Flys quote that Mono has a problem with.
I like Ready2Flys quote, I found it a great way to explain why polyamoury feels natural to me (I liked it so much I put it on my blog).
I don't think that just because something is natural for humans, that every human needs to feel it. There's nothing un-natural, or in-human about hunting, but many people don't feel the desire to do that. It doesn't make it unnatural just because not everyone feels it.
I believe that both Polyamory and Monogomy are natural, in the same way that both heterosexual desires and homosexual desires are natural. Sometimes a person will have one set of desires, sometimes another, sometimes both, but they're still all natural human tendancies.