That's interesting. There is a trend with this kind of sites (I've seen at least one here on HN before). Is it some evolution of joint anonymous blogging/microblogging/pastebins? Or is it driven by an experience - I want to try blogging, let's start by writing, not registering, configuring, skinning, etc?
I don't believe that this might catch on, but as a branch of online self-publishing it could still live a little.