Yes, it will be a turning point to some degree. I suspect we'll see some additional restrictions on number of rounds a magazine can hold.

A couple of other points though. Over the years, I've noticed that most of the hardcore pro-gun citizens are conservative and favor smaller government and less government-funded programs. Yet, these are the same people that constantly say "It is the people, not the guns". Since mental health seems to play a roll in many of these shootings, those pro-gun conservatives are going to HAVE to start favoring additional funding for mental health.

Another thing that I think will happen is we'll take more steps towards bankrupting ourselves by over-securing everything from malls to schools to movie theaters. Just like after 9/11, the fear is going to capture the public and we're going to spend a bunch of money we don't have for a bunch of security theater that won't protect anyone from anything.