The karma inflation says a lot I think.  There seems to be a rash of new users posting less relevant 'link-bait' stories that get voted up for being edgy/funny, but have little interest to hackers.  I've noticed that i've been far less interested in the front page of HN lately due to most of the links on the front page being non hacker news or links I already saw on Reddit(!).  This is purely anecdotal however.