At our company we're building an entirely web-based product that will be used more by businesses than consumers. Early in development we decided to exclude IE6 from the supported browsers list due to the extra development time and associated costs required to make it happen.

I'm all for a simplistic web (I prefer plain-text sites myself) but I think the more sites stop supporting IE6 and instead move towards standards-compliant designs, the sooner IE6 will disappear (and the sooner the big corporations who haven't upgraded will feel the pressure to upgrade).