Gunman named Cho Seung-hui, 23, from South Korea, was in the 4th year of his studies. Police say they haven't ruled out another gunman, but that at one of the guns found on Seung-hui's corpse was used in both the 7.15 am dorm attack, and the 9.15 am classroom shootings. He was a legally resident alien (presumably on a student visa).
As yet they haven't released information on precisely how many guns he had, of what model, and whether they were legally
So while it's not impossible, early speculation that his "Asian-ness" means he's more likely to be the common-or-garden, off-the-rails gun nut than anything to do with Islamic terrorism.
1. Given the magnitude of the massacre, will this have a lasting effect on the United States, or will it vanish into the media after a month?Frankly I doubt it. If Congress tried, the President would likely veto it to keep fans ot the 2nd amendment on side. But I doubt if Congress would even try, since part of the recent electoral success of the Democrats has been to reach out to the sort of people likely to resist stronger controls on gun use and ownership. They aren't going to throw that away when they are hoping to win control over the executive as well as the legislature in the medium term.
So nothing much will happen, politically at any rate, which means the national and international media will get bored ("no change" makes for no headlines) and move on.
What legislative or policy implications will this tragedy have, will it spur lawmakers into some kind of action? Either on a State or Federal level?As I said before, I doubt it will have much effect.
One area I think might be pursued is to restrict the gun ownership rights of legally resident aliens and other non-citizens, which might make the more paranoid feel a little better but is the legislative equivalent of trying to cure a brain tumour with Elastoplast.
3. How can such massacres be avoided in the future?I'm not sure. A few years ago, I would have said the obvious answer was to ban gun ownership. Back then, however, I didn't understand quite how central that idea is to the American psyche. People may kill people, but they would find it nearly impossible to kill 30 or so people in as many minutes with a knife or a bow & arrow*, if for no other reasons than bows having much lower rates of fire, and people being able to run or dodge a knife much easier than they can a knife.
I recall a British would-be multiple killer visiting a junior school with a machete shortly before
the Firearms Amendment was passed in response to the
Dunblane Massacre.
While he tried to kill as many children as Thomas Hamilton, and many were horribly wounded,
Horrett Campbell killed nobody. From which I concluded, loonie with guns = dead kids; loonie without guns = no dead kids. Therefore, ban guns.
By and large, I would say that the ban has worked, despite large percentages increases in urban gun crime in recent years. (The increases are only large in percentage terms, overall murder rates are broadly stable, and an order of magnitude lower than in the USA. And I don't think there is any link between the ban on legal guns and the increase in use illegal ones, but that's probably for another thread.)
But after some years on

, and some thought, a simple ban, or even extended control, just wouldn't work.
For a number of reasons. Politically, it would be nigh-on impossible to legislate. Even if that were not the case, the gun lobby would mobilise massive support, based on that centrality to the psyche I talked about.
And even if someone could magically remove all the practical obstacles, Americans faced with an agressive stranger would assume that they are armed much more often than other nationalities. (This, I think, is the root of the idea that you could stop these multiple shootings by arming everybody else, with no thought to the other possible consequences.)
Even with our supposedly higher rates of gun violence since handgun ownership was banned in Britain (which is highly localised to innner city drug gangs, and even then is at rates that most American law enforcement agencies would be more than happy with), your average Brit would tend to assume that a hostile stranger is NOT armed, certainly not with a gun.
I think guns are tied up in the way Americans feel about themselves and one another in a way unique in the world, and I don't think any kind of ban could be sold to the public.
*Of course, suicide bombing
is comparable, especially where the perpetrator also wants to die, but (as far as we know) this method has not yet been adopted by disaffected youths trying to get back against imagined personal slights from people at their schools or colleges, but by disaffected youths trying to get back at imagined political slights from people in their own or foriegn nations.