I have to admit that I find email rather tedious when it comes to a host of tasks -- like sharing information in a corporate environment. But dead? I don't think so. Though with any luck at all, it's role will diminish with time.
Here's a personal story. I'm secretary of my local home owners association. At a recent meeting one of the board members pointed out how in the last year an organization of which he is a part finally gave in to the push towards email. Now they're using email more and more. To be clear, this person, and the org in question, are not alone. There were nods and murmurs of agreement around the room (including a sizeable number of slack jaws and incredulous stares -- this, after all, is Microsoft land). I didn't mention to them that my family uses Twitter to stay in touch throughout the day. It would have taken too long to explain why we don't just call.