I don't accept having hacks on my websites for the sake of someone else's bad coded, outdated application.
Legacy support is good and convenient but relic support is not, the only thing it does is hold back evolution of the web. Visitors using an outdated browser, without knowing it prohibit us from serving them better and more user-friendly content.
I put a notification on my sites using conditional comments that if IE is lower than 7, the user need to upgrade to see the website correctly. I don't force or prohibit access to the user, but I do nag him by having a notification all the top on his page with a bright yellow color. I am also providing a link to the latest IE version.
This comes from a web radio website where we have about 1000-2000 visits per day,
Out of IE versions we had a 80% using Internet Explorer 6. A couple weeks after look what happened,

Pretty impressive isn't it? Users upgraded because they were notified.
I also thought fast and complete transition to a better version of IE could be 'forced' by Microsoft. Not by making IE8 a required update. Remember how the last version of AOL Netscape nagged its users to upgrade to Firefox? There should be a similar notification for the obsolete browsers by Microsoft.
