Well, all the dutch HN readers will agree it would be "Etter".

But I personnaly don't think this would change much. For me there are two categories of information: private and public. For the private information email is the only solution and for the public solution I have my personal website. People who don't have their own website/blog won't care on who's server the messages are.

* EDIT * I was just thinking, isn't this what sites like blogger are about? You can make a page where you blog, several people can follow you, and they can reply.