Does W3C Validation Have Anything to do with SEO?

I read a blog post today that offers the top 5 SEO tips for 2010.  In the very first tip it says;

Optimise all your code before sending the new website live

• This is likely to become a concluding ranking factor in the near future for the Google SERPs
• Many tools are available to help you optimise your code such as Google Page Speed and Yahoo’s YSlow

I believe they were talking about clean code that loads fast. I’m not sure what they mean by “concluding ranking factor”, because load time has been a factor for a long time now.

But it brought up a question. A lot of people pay a lot of attention to W3C Validation. It’s a selling point for some web design companies.

But is it or will it be a factor in search engine rankings in the future?

Google.com 45 Errors, 2 warning(s) when I checked.

Yahoo.com had 141 Errors, 28 warning(s)

Bing.com had 12 Errors.

Searching for the term auto parts in Google and the top result is Advanced Auto Parts, 358 Errors, 162 warning(s).

Searching for the term real estate in Yahoo and the top result is Realtor.com, 137 Errors, 4 warning(s)

Searching Bing for the term airplanes and the top result is Wikipedia and that page validated. The number 2 ranked site for airplanes is Airplanes.com, 35 Errors, 17 warning(s)

So besides the Wikipedia result, none of the top ranked sites validated. This is by far not a complete study obviously, but I used 3 different random terms and top results for those terms did not validate and nether did the search engines’ own pages.

So, do you believe that W3C validation has anything to do with SEO?

Can you show examples?