Often, folks ask us why we continue to support IE6. The short answer is that because we've committed to doing so. But more importantly, even if we dropped support, most people who want to use IE6 would still use it anyway, just without the benefit of security and reliability patches. Putting customers at risk isn't an option.
Having said that, we work hard at evangelizing new browser releases and getting folks to upgrade. While we still support IE6, there's no question that users on IE8 will have a more secure, reliable, and performant experience, and we want everyone to benefit from our hard work over the last few years.
The folks over at Digg recently did an interesting survey of their IE6 users, asking, in essence, "why haven't you upgraded?" The dominant answer (32%+37%=69%) was that "I'm not allowed by my IT department, and I don't have permissions to ignore them."
Hopefully, these numbers will shift in the near future when Windows 7 is released. Windows 7 will generally have IE8 installed by default, and IT staff worried about one or two legacy webapps that require IE6 can rely on "VirtualXP Mode" to run those incompatible webapps until they are retired.