The spreadsheet seems to tell us that the swine flu has a more lethal variant in Mexico than elsewhere. These viruses are capable of quickly mutating as we saw with SARS. Is it possible that this one has mutated to a less deadly but more easily spread version already?
I'm certainly not a doctor or virologist but it seems, from the relatively mild NYC cases that we may have dodged a bullet here. Of course, it could just as easily mutate to a more deadly form just as quickly.