Alright, so no doubt the school shooting in Newtown is a tragedy; committed by some psychopathic asshole with a blatant disregard for human life. Let's just put that little disclaimer out there right now.

Instantly I can already tell there will be people saying "People shouldn't even have guns, there's no need for guns." Firstly, do you think if an authority figure (say a principle) had a gun that the aforementioned asshole would have been able to kill as many people as he did? Most people who legally purchase a firearm do not intend to use it unless it is a matter of personal safety. There's also a screening process and a waiting period for weaponry; instituted around the time of Prohibition, that prevents every asshole from getting a gun. It only lets people who are very good at hiding the fact that they're assholes get them for malicious reasons.
Secondly repealing anything from the Bill of Rights "as a matter of public safety" would be a terrible idea. Once the precedent is set, judicial review and legislation WILL base new laws on it, that is a fact. Here's an example. Thousands of people commit suicide every year. Thousands of teens commit suicide every year as a result of the way other people treat them. Of the speech (included in the Bill of Rights) that others use to cause harm to the receiving party. People could say "Well some people who have no clue how to act in society are using their first amendment right and cause people injury or death, lets take it away from everyone." As you can see, this is a stupid idea, but it's the precedent and the same line of thought that's being used by people against the Second Amendment.
Listen to me, it is a tragedy an abomination that someone would do what the shooter at Newtown did. But to apply the constraints you would put on a madman to everybody is not how a free world should work. A simple solution (which I believe in) could be to implement a psychological test into the registration for a firearm. If you're under say... thirty, you have to have a psychological test by a licensed practitioner in order to acquire any grade of a firearm.

My heart and prayers are with the families of the deceased, but I feel like the capitalization on tragedies needs to stop, and people need to really think about what they're agendas would cause before supporting them.