Designing A Replacement for E-Mail?

Really interesting commentary over on Dan Rubin‘s SuperfluousBanter, “Email Doesn’t Scale,” which is about wanting to start thinking about designing a better form of online communication than e-mail. With some thoughts of his own and some links to other people who have been thinking about the same idea, it’s one of those sorts of things that sounds completely insane when you hear it at first (“Who would ever want to see television in color?!”), but then as he gets into it, it sorta does kinda make sense.