Yes we still get hit by people who use older browsers with multiple versions. There are people who do not upgrade and they are our customers. If this is the environment that you want all the federal web developers to live in, then you may not get much support. I am trying my best to Educate and Outreach to plant seeds on what is coming and to let them hear this for the first time. Most people do not know that PDF can be posted as long as there is a HTML version.
Most people have no ideas what CSS is.
This is not going to happen and you will be alienating the web developers that you want on your side. They have no money for training and I see no plans where funds will be allocated by the Rehab Act Section 508 to provide for training. They can still use HTML 4, tables for layout and without depractated fonts. Get them to this point and give the web developers time to adopt CSS and hopefully someone will detail when CSS blows up in different versions of Netscape. But unfortunately tables are a big part of life in the government and CSS is not.