Matt Cutts in his recent video in April 1st stated that Google will not stop updating the search result as they want to serve better to their user and they will continue grow more with the user experience. Matt also added the search results will always be changing, the result of that change is "flux".

In this video he also said that Google needs to be change due to change of web, user, devices and also the spammers and their technique. If you think the results are perfect today you might think differently too as Google will work on making them more perfect in the future.



For SEO you need to be on your heel as you need to be updating and changing as well.