What about taking a crowded subway car out of Chinatown in NYC in 4 months! NYC and a few other urban centers in America are the big risks here. The rest of the country with the evil automobile commute and spread out suburbs make us a lot less likely to have a real problem. The living conditions and war in 1918 lead to a lot of the deaths from the Spanish Flu. Of course the reported death rate for that influenza was 1 %. That is not comforting.
If we can somehow stabilize the spread of it, we'll be fine. West Nile Virus killed five people in Houston last year, and the world didn't end (except for those poor souls). There haven't been any SARS deaths in the entire country, yet.
But as long as the numbers are increasing in spite of all our efforts, it's a huge concern.