When you say that no one seems to be doing much, are you sure that's not just because the efforts don't get much publicity?

There is a lot that's being done:

Most nuclear-armed governments have massively reduced their nuclear weapon stockpiles, and try to stop other countries getting nuclear weapons. There's an international effort to track fissile material.

After the Cold War ended, the west set up programmes to employ Soviet nuclear scientists which have run until today (Russia is about to end them).

South Africa had nuclear weapons, then gave them up.

Israel destroyed the Iraqi and Syrian nuclear programmes with airstrikes. OK, self-interested, but existing nuclear states stop their enemies getting nuclear weapons then it reduces the risk of a nuclear war.

Somebody wrote the Stuxnet worm to attack Iran's enrichment facilities (probably) and Iran is under massive international pressure not to develop nuclear weapons.

Western leaders are at least talking about the goal of a world without nuclear weapons. OK, probably empty rhetoric.

India and Pakistan have reduced the tension between them, and now keep their nuclear weapons stored disassembled.

The US is developing missile defences to deter 'rogue states' who might have a limited nuclear missile capability (although I'm not sure why the threat of nuclear retaliation isn't a better deterrent than shooting down missiles). The Western world is paranoid about nuclear terrorism, even putting nuclear detectors in its ports to try to detect weapons being smuggled into the country (which a lot of experts think is silly, but I guess it might make it harder to move fissile material around on the black market).

etc. etc.

Sure, in the 100 year timeframe, there is still a risk. It just seems like a world with two ideologically opposed nuclear-armed superpowers, with limited ways to gather information and their arsenals on a hair trigger, was much riskier than today's situation. Even when "rogue states" get hold of nuclear weapons, they seem to want them to deter a US/UN invasion, rather than to actually use offensively.

Obviously the crux of the issue is whether the official probability estimates and predictions for these types of threats are accurate or not. It's difficult to judge this in any individual case that fails to develop into a serious problem but if you can observe a consistent ongoing pattern of dire predictions that do not pan out this is evidence of an underlying bias in the estimates of risk. Preparing for an eventuality as if it had a 10% probability of happening when the true risk is 1% will lead to serious mis-allocation of resources.

It looks to me like there is a consistent pattern of overstating the risks of various catastrophes. Rigorously proving this is difficult. I've pointed to some examples of what look like over-confident predictions of disaster (there's lots more in The Rational Optimist). I'm not sure we can easily resolve any remaining disagreement on the extent of risk exaggeration however.

Maybe at first, but I clearly recall that the hype was still ongoing even after it was known that this was a milder flu-version than usual.

And the reactions were not well designed to handle the flu either. One example is that my university installed hand sanitizers, well, pretty much everywhere. But the flu is primarily transmitted not from hand-to-hand contact, but by miniature droplets when people cough, sneeze, or just talk and breathe:

http://www.cdc.gov/h1n1flu/qa.htm

Spread of the 2009 H1N1 virus is thought to occur in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing, sneezing or talking by people with influenza. Sometimes people may become infected by touching something – such as a surface or object – with flu viruses on it and then touching their mouth or nose.

Wikipedia takes a more middle-of-the-road view, noting that it's not entirely clear how much transmission happens in which route, but still:

http://en.wikipedia.org/wiki/Influenza

The length of time the virus will persist on a surface varies, with the virus surviving for one to two days on hard, non-porous surfaces such as plastic or metal, for about fifteen minutes from dry paper tissues, and only five minutes on skin.

Which really suggests to me that hand-washing (or sanitizing) just isn't going to be terribly effective. The best preventative is making sick people stay home.

Now, regular hand-washing is a great prophylactic for many other disease pathways, of course. But not for what the supposed purpose was.

It wasn't just the media:

Take the response to the avian flu outbreak in 2005. Dr David Nabarro, the UN systems coordinator for human and avian influenza, declared: ‘I’m not, at the moment, at liberty to give you a prediction on [potential mortality] numbers.’ He then gave a prediction on potential mortality numbers: ‘Let’s say, the range of deaths could be anything from five million to 150million.’ Nabarro should have kept his estimating prowess enslaved: the number of cases of avian flu stands at a mere 498, of which just 294 have proved fatal.

...

On 11 June 2009, just over a month after the initial outbreak in Mexico, the World Health Organisation finally announced that swine flu was now worthy of its highest alert status of level six, a global pandemic. Despite claims that there was no need to panic, that’s exactly what national health authorities did. In the UK, while the Department of Health was closing schools, politicians were falling over themselves to imagine the worst possible outcomes: second more deadly waves of flu, virus mutation – nothing was too far-fetched for it not to become a public announcement. This was going to be like the great Spanish Flu pandemic of 1918-20. But worse.

However, just as day follows nightmares, the dawning reality proved to be rather more mundane. By March 2010, nearly a full year after the H1N1 virus first began frightening the British government, the death toll stood not in the hundreds of thousands, but at 457. To put that into perspective, the average mortality rate for your common-or-garden flu is 600 deaths per year in a non-epidemic year and between 12,000 and 13,800 deaths per year in an epidemic year. In other words, far from heralding the imagined super virus, swine flu was more mild than the strains of flu we’ve lived with, and survived, for centuries. Reflecting on the hysteria which characterised the WHO’s response to Mexico, German politician Dr Wolfgang Wodarg told the WHO last week: ‘What we experienced in Mexico City was very mild flu which did not kill more than usual – which killed even less than usual.’