The gov has a site about how to be prepared against such attacks -- I didn't look through it in detail to know how good it is:
http://www.ready.gov/
One thing, which at least eliminate one of the most devastating biological attack would be to allow people to at least voluntarily get smallpox vaccine.
Thanks for the site, FairOpinion. However, I find that site nearly useless. I gain nothing from this other than "watch TV" or "listen to the radio." I want to be proactive.