Atomic - 7:10 pm on Jul 8, 2010 (gmt 0)
About two years ago I redesigned several of my sites so they were tableless, pure CSS etc. My rankings climbed steadily. I also redesigned a site last year that was made in 1996 so that it was pure CSS with a tableless design. It dropped a little bit for a few keywords, but most still rank as well as they ever did. Many of these keywords outrank Wikipedia for common, popular terms.
I see no problem with CSS if it's done right.