For SEO professionals, Pagerank was a handy little unit of measure in assessing websites. It was never an "end all be all" goal, but it did help to simplify the complex world of search, even though it didn't really dictate ranking order.
Google has been investing in ranking factors that are more dynamic and real-time than link relations. With the ubiquity of social media and sharing, Google has begun to infuse search with social tendencies and data. Comments, Likes, Pluses, and re-posts are now all factors in real-time search results, which have an effect on rankings.
Pagerank, by consequence, has begun to lose out. Google has ceased to stress it's significance, and with no update in values to Pagerank for the past six months, it's becoming increasingly clear that our previous unit of measure is losing out to a more dynamic world.
As Barry Schwartz of SearchEngineLand.com recently stated:
Google’s failure to update the PageRank values might effectively be killing it, all the same.
Google has expressed that frequently updated pages get a boost in rankings (QDF). Depending on the types of search, freshness may be a factor in the types of results Google delivers. Freshness is one of 200 signals that help shape the results of search. Although this is not to say that freshness is the signature factor in ranking... It really depends on the type of search a user is conducting. Google's job is to match the search intent of the user with the closest results.
Take a look of this video of Matt Cutts from Oct 2012 explaining the relative importance of "freshness" as one of the ranking factors.