According this post on the blog site, TechCrunch, Facebook will be releasing a full-blown Web mail client for its 400,000,000 users (yes, 400 million). Apparently, the internal rally cry at Facebook is to take on Gmail.
For years, the pundits said the proprietary email systems of the early social networks were walled gardens. The benefit was that they restricted spam and unwanted communications. But in the end, I think consumers prefer open and unfettered access, and they are willing to put up with some annoyances to get it.
Long live email.