An interesting development in Google's ranking algorithms is that Google is now checking for Over Optimisation on sites!
This means that if you have hired unscrupulous SEO people to optimise your site using unethical techniques (of which you might not even be aware!) you may end up getting penalized in the near future.
The good news, though, is that you won't be penalized if you've got a site that has good content and you haven't done too much SEO.
The idea is to even the playing ground a bit so that smaller sites with excellent content still get a chance to rank well.
The original article with details for those interested has a few more details and is well worth a read:
(Thanks to Meri Harli of Meriwords for this link!)