It might be worth mentioning how IE 6 is still there. IE 6 is the only version that ever came with Windows XP and 2003 install images, which many many corps still use. And remember that the average lifetime of a Windows installation on a corporate desktop is actually pretty short, getting wiped and re-imaged frequently as people leave or machines are moved around or some Outlook error pops up and the IT guy re-images because that's faster than digging in to fix it. So IE 6 comes out of the reinstallation casket all the time.
It's not that corps are scared of upgrading, it's just not worthwhile from a cost-benefit standpoint to download and install IE 8 on every single machine on every reinstall. Their users that want IE 8 or Firefox will go get it; the users that don't know what a browser version is never know that they're missing anything. IE 6 will only go away when Windows XP does.
FWIW, I intentionally keep IE 6 on my work machine (not a big corp, but we sell to them) for testing, and use Opera for real browsing.
"In order to help web designers and web developers test their websites in older versions of Internet Explorer, we've provided the following VHD with Windows set up with the specified version of Internet Explorer. The images are patched with the latest security updates and are otherwise clean installs of the operating system with very few modifications."
"Note: You may be required to activate the OS as the product key has been deactivated. This is the expected behavior. The VHDs will not pass genuine validation. Immediately after you start the Windows 7 or Windows Vista images they will request to be activated. You can cancel the request and it will login to the desktop. You can activate up to two “rearms” (type slmgr –rearm at the command prompt) which will extend the trial for another 30 days each time OR simply shutdown the VPC image and discard the changes you’ve made from undo disks to reset the image back to its initial state. By doing either of these methods, you can technically have a base image which never expires although you will never be able to permanently save any changes on these images for longer than 90 days."
Enterprises like to centralize everything then they get trapped into the trap that they set for themselves. Nature and people are decentralized, technology should be the same. Imagine if there was only one tree responsible for the oxygen on Earth. Let people manage their own desktop environments already!
Indeed, many enterprises such as the one I work for do not care about Google apps etc.. not working since they usually cater their browser versions towards in-house software development.
