If you want to get people in large corporations using your site, you have to support IE6 for a while longer I think. I've worked in a few of these, and they all move extremely slowly in upgrading. I can see some of them keeping IE6 for at least another year or more.
I know I hear you. It definitely should be done but I'm not even sure if it's possible. I'll begin looking more into it shortly. At the moment, not a single feature or layout segment is operational.