An interesting look at email in the age of Twitter and blogs.
The shift away from email by non-business users is apparent to anyone with teenage kids. Mine communicate with their peers via IM and texting; email is for fogeys like mom and dad.
I agree that email will remain the choice for enterprise use, but I wouldn't underestimate the infiltration of tools like Twitter as people become habituated to their use off the job and younger workers enter the job market. As competitors to email become part of daily life, IT departments will have to cope with them whether they want to or not.