The other issue is that many corporates/educational simply don't support or let you install another browser. This is the single biggest issue, methinks. Even

The other issue is that many corporates/educational simply don't support or let you install another browser. This is the single biggest issue, methinks. Even at my company (> 100 people), the majority of non-technical employees do not have the ability to install software on their machines. Our IT department allows technical users to do whatever we need to do, with the caveat that we have to clean up our own messes. That said, the base Windoze installation here includes IE7.