I may be going out on a limb here, but I think it's important to get this out since panic can kill just as easily as inaction.
From a variety of sources, including some in Homeland Security, this is what I think I know:
It is a unique strain of swine flu combining genetic material from pigs, birds and humans in a way researchers have not seen before.
CDC officials described the virus as having a unique combination of gene segments not seen before in people or pigs. The bug contains human virus, avian virus from North America and pig viruses from North America, Europe and Asia. It may be completely new, or it may have been around for a while and was only detected now through improved testing and surveillance, CDC officials said. -- Associated Press
It is apparently transmitted both by contact and aerosol (coughing, etc.) Because of its characteristics, it was thought by some that it might be a designer, i.e. weaponized, virus deliberately set loose. This is now thought unlikely for two reasons: first, it is not universally deadly and second it apparently responds to Tamiflu and Relenza.
Roche, the maker of Tamiflu, said the company is prepared to immediately deploy a stockpile of the drug if requested. Both drugs must be taken early, within a few days of the onset of symptoms, to be most effective. -- AP and confirmed by DHS/CDC sources (MBV)
The cat is out of the bag, and this flu will run its course across the world. There will be no quarantine containment. DHS believes the Mexican statistics are certainly understated as to size of infected population and death rate (6% claimed, likely at least double that). Of the few US cases admitted, none have died. The difference may be that a. DHS is trying to keep a lid on panic by understating statistics, b. that the increased comfort distance of Americans versus Mexicans minimizes spread, (Also, Mexicans are more likely to kiss each other and shake hands than the average American) or c. that American access to excellent health care and early intervention plays a key role in survivability.
The fact that the Mexicans report that the mortality of the virus seems to hit hardest at the 25 to 45 year old range is consistent with the 1919 flu pandemic and this as much as anything has scared folks in DHS.
The defensive protocol seems to be N-95 or better medical masks (get them while you can, they'll be drying up by next week when the panic really hits) and access to Tamiflu. Handwashing, of course. Stock in hand sanitizers should shoot through the roof. Wear masks when out. (Although there is some argument about definitive utility of masks, it is certainly better to be masked than not.) Depending upon how bad this gets (and especially whether it mutates again into something more vicious) stock up on things you don't want to have to go out to get: fuel, food (don't forget the pets), bottled water, etc. (This flu, though a swine variant, reportedly hits harder with vomiting, diarrhea and dehydration than classic swine flu.) Make no unnecessary trips. (Home schoolers got it made.)
A question to a friend with DHS sources about protocol brought this response:
"Yup, The CDC standard. It doesn't seem to have any "mythical" Hollywood movie qualities. Seems to be most lethal in the 21 to 45 age group...the folks at CDC are all over it, but can't draw an conclusions yet. Most curious is combining ability of so many different virus into one "bug." Could be a test bed gotten loose, for a different bio-warfare bug we haven't seen yet. We'll see. Good news on this one is that it really doesn't like Tamiflu and other anti-virals, and there are lots of those available. Take within 48 hours of symptoms showing and you should be good to go."
I am waiting for more information from a variety of sources and will pass it along as I get it. In the mean time, take preps. Get those N95 or better masks first, and get them to fit all your loved ones. Remember, they're expendable items like ammo and lose their efficacy after a while. Buy as many as you can afford. The ones that fit smaller faces are available (for now) though harder to find.