Oh, Copia isn't some "other" book reading site? Maybe Nate should come and clarify some things for us all then...
edit:
After some help from my friend google, here's what I found:
http://www.thecopia.com/
It appears to be a site that is trying to be a whole ecosystem. Physical reader, ebook store, twitter/goodreads plugin, some sort of app on your computer [?], and discussion forum.
I'm confused more than anything after visiting the site. I know it is a beta site so all the kinks aren't worked out yet, but what is the core mission of these people?
Could be cool...