what I meant was to shift our mindset. At least for me it has always been a matter of honor to support all clients out there as equally well as possible just because that's what we have done on the web ever since.

What I was thinking was to not do it this time around. Now if your customer insists, explain the issue and add the IE tax (I'd say an additional 80% of what you'd charge for the real-browser-only version). If your employer insists, well, then you don't have too many options of course.