The responses that use valid arguments (i.e. not "it will harm your professional reputation to use tables! or tables are for tabular data! or I can bill more hours if I use CSS!") pretty much agree that the arguments against tables don't hold much water.

The only argument that might be important against tables that I could see is that they work less well with screenreaders. Can anyone using a screen reader confirm or deny this? I could easily see it being the other way around, because with tables a screen reader will let you quickly navigate to different parts of the page (e.g. sidebar to header to main content by going left, right, up and down instead of painstakingly navigating over a bunch of text).

On the other hand, tables are easier to use, more flexible, more predictable across browsers, and more readable. Just look at the years and years of research it took the CSS experts at e.g. Alistapart to replicate layouts that are trivial with tables using CSS.

Examples:

http://www.alistapart.com/articles/fauxcolumns/

http://www.alistapart.com/articles/fauxabsolutepositioning/

http://www.alistapart.com/articles/multicolumnlayouts/

http://www.alistapart.com/articles/negativemargins/

And even then it doesn't always work: http://www.satzansatz.de/cssd/hgjump.html

Note that these layouts are utterly trivial to create with tables.

They also don't work very well if you're trying to build a site that looks decent on a mobile browser... You can do some cool CSS tricks to facilitate different screen sizes. See http://cssgrid.net/ for an example (resize your browser window and see how things change)