Ok, Google finally made an official statement that they do not use the META tag “keywords” in their search ranking.

At least for Google’s web search results currently (September 2009), the answer is no. Google doesn’t use the “keywords” meta tag in our web search ranking.

Also, a very interesting snippet of information in the same post was this:

Even though we sometimes use the description meta tag for the snippets we show, we still don’t use the description meta tag in our ranking.

However, this does not by any means mean that you should start disregarding META tags altogether! Although Google is the king, czar, president and emperor of search engines at the moment, adding contextually meaningful keywords (ie: stuff that’s also actually in your content) with a META keywords tag will definitely not hurt in the future either.

As far as the META description tag goes, as noted above, it is still used in providing a summary of the content and good SEO always goes beyond ranking and considers thinks like click conversion, so a strong and meaningful summary in your META description will still be very beneficial.