Those who pay attention to public health and epidemiology generally agree that we should all be really, really freaked out at the prospect of a major global epidemic.
While public health experts remind us that any successful model for preventing (or at least containing) such an outbreak will have a number of moving parts, many of which are now missing -- greater foreign aid for health care in the developing world, full implementation of international public health agreements and reporting infrastructures, rapid response ability, more open access to scientific information, etc. -- one thing we know we need is better understanding of how diseases work as organisms.
We've just taken one big stride: an international team of researchers, working in a maximum-security biocontainment facility and using "reverse genetic engineering," has recreated the influenza strain that is believed to have killed 50 million people in a 1918 pandemic, thus allowing new understanding of what made it so lethal, and how it might have been treated or vacinated against.
"Scientists say that the disease leapt to humans by mutating from bird flu, possibly after passing through pigs, which are able to harbour both human and avian viruses and thus allow them to swap genes as the viruses reproduce. For that reason, experts are deeply concerned that the avian flu that has broken out in poultry flocks in parts of Southeast Asia may acquire genes that will make it highly infectious as well as lethal for humans.
[This research] adds strongly to suspicions that what made the type A 1918 virus strain so extraordinarily vicious was the unique profile of its HA gene. That finding opens up good avenues for diagnostic tools for spotting emergent viruses with this genetic signature, thus tackling an outbreak in its early stages.
"Once the properties of the  HA gene that gave rise to its lethal infectivity are better understood, it should be possible to devise effective control measures and to improve global surveillance networks for influenza viruses that pose the greatest threat to humans as well as other animal species," the authors say.
Such purely technical victories will of course lack true meaning without the political will to rebuild an international public health system capable of making use of them, but, at the same time, it's also breakthroughs like these which may well prevent the next Black Death.
(Thanks to Bill Cronin for the link!)
UPDATE -- Tim Bishop has posted some provocative ideas on bird flu, public health and worries of an epidemiological perfect storm, while Quinn goes on to say "Fortunately, like Ebola, hardly anyone gets the bird flu, and it's very hard to transmit. Unfortunately, if a person who already has a human flu virus swimming around in them gets the bird flu as well, they could easily swap a few genes and start doing something Ebola will almost certainly never do; hang around on kitchen counters and doorknobs and in hugs and kisses. Then we have a problem."