Sixty-eight deaths from around one thousand infections is a lethality of 7%. That alone should make us take this very seriously until we have more data.
In the State of Mexico (metro area of Mexico City) there has been 3 deaths out of 44 cases of Influenza (not all confirmed to be H1N1) which is 6.8% lethality
Update: On San Luis Potosi (some 400Km north Mexico City, second biggest outbreak) has been reported 62 cases and 5 deaths, 8% http://bit.ly/15VOOt
In these sorts of situations, people who have mild cases of the same strain don't even seek treatment. That means the denominator -- the actual number of infections -- is much higher than initial/limited reports, and the fatality rate correspondingly lower.
So far, all confirmed cases in the US have been mild. And they probably caught it from others who got over it without triggering any alarm. So don't head for the hills based on early fatality extrapolations from Mexico just yet.
