They do look nice, very nice in fact.
I am confused by what you mean by "css only" though. Your skins are table based, css only, to me, means layout using only divs and using tables for their original purpose, representing tables of data.
Here is a simple div based dnn site - http://www.damnwitty.com/ - the only tables in the page come from the modules.
www.obrienit.se