Is spam going to kill SMTP?

I read this post about the scale of the spam problem today. Its pretty chilling, but I guess it was meant to be. As far as I can tell the question it poses is, are we're really looking at a doomsday scenario and if so should we now be considering the unthinkable and pull the plug on SMTP?
I'm assuming that we all agree that the problem of spam is a direct result of SMTP being designed without any of the controls necessary to protect the network from this abuse.
Can SMTP be revised or does it need a flag day? I don't want the character of email to change, but I'm fed up with trying to explain why the problem of spam is so intractable, perhaps its time to get some traction and stop flogging a dead horse. WDYT?