In a recent video by Matt Cutts, Google's head of search spam, said that it will continually get harder to take short cuts and spam Google.
Month to month, Google is often releasing algorithm updates to improve search quality. Google is constantly looking to improve the search results. Part of this is combatting spam techniques.
Matt guarantees you that Google will continue to make the search results better. You will always have to adapt and evolve to that but that can be minimize if you have a great site, Matt added.
Here is the video:
Forum discussion at Twitter.