Mark Zuckerberg just held a presentation to unveil Facebook's "next generation messaging" system. He repeatedly drove home the idea that "this is not email," nor is it "an email killer." Their plan is to tie together multiple forms of communication — email, texts, social updates, etc. — and blend them into conversations. As users go about their days, interacting with a variety of devices, the communication method automatically updates to whatever is appropriate at the time. If a user receives an email while he's at a desktop, browsing Facebook, it will bring up the message in a Facebook chat window. If the user is browsing on a smartphone, it will bring up the message there, instead. If it's a dumbphone, then a text message can be sent. Another central feature is the idea that conversation histories from multiple sources and different forms of communication can be integrated through Facebook, so that you no longer have to separately root through IM logs, SMS logs, old emails, etc., to see old correspondence. (Users will have the ability to delete these, should they desire.) The last major feature they mentioned is what they call the "social" inbox, which is based on whitelisting. Users will be able to set up primary inboxes which only display communications they definitely want to see, while leaving low-priority messages, spam, and all the other noise typical to email in an inbox they check less frequently. The new system will be rolled out slowly over the next few months.