If you want to kill a lot of people there are much easier way than messing around with anthrax bugs. If you want to frighten a lot of people I suppose setting off a scare like this and relying on the existence of the kind of twisted people who make hoax fire alarm calls and play around with computer viruses for fun is a good way.
The thing to remember is you are far far more likely to get killed in a road accident than any of this stuff. Not worth worrying about. If you work in a sorting officer you should be careful about suspicious packages anyway. Nothing new here really.
I'd like to hope that this could wipe out the junk mail companies overnight.