A recent conversation with a web consultant I had got on the topic of browser support. I asked "What browsers do you support?". He responded with the list of the usual "modern" ones: IE7+, Chrome, Firefox, Safari. "How about IE6?" I inquired. "Well, it is a hassle. What I usually do is add an extra charge for IE6 compatability. When the clients sees it, they usually drop that requirement. Normally, if you ask them whether it is important to support IE6, they say yes and then it's your headache. But showing them the price tag seems to work well."
This makes sense to me: making the cost of IE6 explicit is something that can hasten the departure from supporting this legacy browsers. People tend to be very careful with their money when they feel they are not getting the greatest return on it, and I have a feeling that a lot of clients would not want to spend extra on making sure their site works in the half-dead zombie that is IE6.