Hm. Don't even think about starting to support _all_ of these "channels". The moment you are using Javascript and CSS you are usually lost, but nevertheless they are an important help in increasing positive site experience and usability.
Very often non-web-savy people critizise web frontends (they are allowed to do!) and not using any technology that lies around to support them and is called "standard" would be a shame.
The human resources you need to distribute your content to all that hype or not hype targets are tremendous, it's definitely not done with fixing some tables. You need specialists for every channel or days and weeks of research. Browsers are enough for that battle, imho. You know that one page in XY browser version Z can look differently on the same browser and version just on a different operating system due to different implementations. And you know that Javascript support can change from subversion 4.6 to 4.7 or even 4.6a to 4.6b. So with CSS. It's simply not worth to claim that product X (e.g. OpenACS) delivers browser independent markup.
Maybe the current discussion is just a natural consequence of the style and layout change / efforts. Also it's ok that Vadim originally notified the community that NN4.7 crashes. But, imho, supporting WebTV, Konqueror, Netscape, Mozilla, IE, Opera, and of course, Lynx (both, the one with and without color and frame support, of course), maybe WML, Users that life in the 640x480 world (256 colors) ... that is really the job of the people deploying the toolkit in a real project.
my 5 cent.
