I hear this claim floated a lot, and I largely believe it based on anecdotal evidence, but how do we know this is really true? Has someone done a study or have a meaningful way to measure it?
Edit: A quick way to verify this is to run your webserver logs through "whois" for clients with IE6.
This will change when there are applications on the internet that corporates need, but can't access via IE6. See GWave for an example of how this can be resolved.
Companies aren't getting onboard the usual sharing is caring experiece that most netizens are familiar with - they usually want to pay $$ to get a product (e.g. sharepoint) that provides some level of support rather than asking the users to be smart.
It may happen, but my bet is that internal net usage changes when the baby boomers have left the workplace and been replaced by people brought up in a very technological world.