Tantek is fighting an uphill battle in his quest to rid the world of email. Email is ingrained, ubiquitous, and everywhere. Every person that regularly logs on to Hotmail or Gmail contributes to this entropy. While I would love to see email die as much as anyone, right now, there just doesn't seem to be a better alternative.
I do enjoy Twitter a lot despite its somewhat pathological addictive qualities, but I'm often struggling with expectations that I'll be constantly logged into Skype, IM, or IRC. I don't deal with this well at all. These things pollute my workspace with a sea of tiny windows and lead to a worse state of continuous partial attention than even Twitter does. Email gives me better control over the cognitive load because I can choose to check it at periodic times and the read/unread distinction provides a primary method of staying up to date that isn't dependent on my being online and checking my inbox continuously. I'm not saying I'm the same as everyone else, but I find IM and chat communication far more disruptive to my flow than most other facets of online communication.
Email might be backwards, unscalable, and the primary cause of the massive swelling of spam that's clogging todays interwebs. If you live in a world of continuous partial attention, maybe IM focused communication is fine, but what about the millions of regular people who don't spend their lives plugged in to the matrix? For them, checking their email once every few days is the perfect solution to staying in contact and making connections. This point to point style of communication makes sense to normal people. Until the day when everyone has a URI rather than an email address as their primary interface to the network, I think we need to focus on making email better rather than ignoring it altogether.
Another thought - maybe everyone communicates differently and prefers different tools and mechanisms to take their communication online? How can we mesh these systems, so that the email focused people can still effectively connect to those who don't care for email anymore?