A few things:
1) If IPB3 phases out IE6 from it's code, and most webmasters upgrade (especially big networks with tons of visitors), that's the main push needed to end the IE6 horror
2) A bit earlier, I saw the argument of people not bothering to upgrade since they don't have the time. All you need to do it put up a big red banner with the words: WARNING: This site will be phasing out support for Internet Explorer 6. If you continue to use it, some features of this site will stop working. You may upgrade to the latest version of Internet Explorer HERE and include this link: http://www.microsoft.com/windows/internet-explorer/worldwide-sites.aspx. Web users that haven't been smart enough to go to IE7 will think it's really important, and immediately upgrade :shifty: