Facebook Messages - it's not email, people (except it is)
IT'S NOT EMAIL. Whatever you made of Facebook's announcement yesterday, IT'S NOT EMAIL. But what about the fact that Facebook are giving users a @facebook.com email address to use? Oh. Erm. IT'S NOT EMAIL. Gotcha.
It is email, really, but Facebook Messages is an email system built of top of the existing platform, which means you can customise the privacy settings so that you only receive email to your Facebook address from your Facebook friends - although you can also opt-in people who aren't on Facebook. It'll also aggregate messages sent by SMS and Facebook Chat and organise them by person, rather than subject.
Interesting? Yes. Email killer? Not in the slightest. It's an aggregator for people who spend most of their time in Facebook - it'll find a home with some users, but it won't disrupt the online habits of everyone else.