This is a great step towards making the Facebook useful again. Before the app spam was allowed, the News Feed was a handy place allowed me to get the news about the actions generated by my "Friends".
After the apps were unleashed and figured out that spam was the way to grow, my News Feed has turned into a whole bunch of Flixter notifications "that X challenged Y to take a movie quiz" with X and Y being any two random people from my friends list. Or that I received a video message from Z, even though I didn't.
In short time, most of the content on my News Feed was app generated junk.
After getting tired of Flixter producing this spam on my friends's feeds, I've uninstalled it, as well as all of the ****-walls. It's a shame, Flixter could be a useful community application but they shot themselves in the foot by being unscrupulous in their user acquisition tactics.
The next great step would be if I could mute news about specific apps even if those actions were actually initiated by the users. I really don't care if someone turned vampire or became a pirate...