When SEO-companies and site owners try to catch up with constant changes of search algorithms, Search Engines try everything to stop them from doing it. They make secrets of almost everything they use creating SERP. Before we knew that PR in Google is not the only factor, now it’s almost clear that PR is even not a major thing. Still Google keep promising some sort of smart search and spends money creating artificial intelligence (
http://news.com.com/2100-11395_3-6160372.html).
Even now it’s complicated to make sufficient influence on search results, what can we expect in future?