The more recently discovered that the more people use div+css this is called to represent XHTML. This is fundamentally incorrect!
One is that CSS is a technique called style sheets (stylesheet). Others call it cascading style sheets (cascading Stylesheet), and Div is a label in HTML. div and table are siblings, so you should not put a div and CSS together to represent XHTML.
Second, DIV+CSS does not necessarily conform to standards, XHTML and not just div+css. Many of the sites or forums that have been refactored using div+css are inherently unable to pass w3.org verification. (for example, the web forum and Vtbbs are simply not able to pass the w3.org XHTML checksum.) Even though the calibration only indicates that it is syntactically correct, a considerable number of sites are suspected of abusing div.
So please do not be overly infatuated with DIV+CSS.