You can check out the official announcement here.
Facebook answers the question about how will affect pages with the following:
Will this affect my Page?
The vast majority of publishers on Facebook are not posting feed spam so they should not be negatively impacted by these changes, and, if anything, may see a very small increase in News Feed distribution.
A smaller set of publishers who are frequently and intentionally creating feed spam will see their distribution decrease over the next few months. We’re making these changes to ensure that feed spam content does not drown out the content that people really want to see on Facebook from the friends and Pages they care about.The Next Web gives their views on the changes here.
Facebook, however, doesn't address how it will filter out the spammy, like-baiting posts from people who are legitimately trying to increase their views by encouraging their followers to like, share or comment or are running contests with those specifications.
What are your thoughts? Is this a good thing? How will it change how you market to your fanbase if you're a person who tries to run contests with like/sharing/comment posts?