That is exactly the question I was asking my self not so long time ago.

And when you need to get an answer you usually ask "google", Which is exactly what I did.

Any way if that interests you please visit our "bookmarking" template

and look at the "xhtml" category. here is the link:

Nukenotes/why xhtml?

I think you will find there some interesting articles.

From some emails I got seems to me like some people are thinking that a table-less layout is like kind of Iron-less cement.  Well actually valid xhtml is  heavy duty. :)

Valid xhtml, table-less Containers and skins will work with all dnn modules, perfectly fine.

Enjoy reading!