Not the manipulated toner cartridges! Not those! Whatever shall the terrorists hit us with next?!?
The problem is not the amount of people who could have potentially been killed in this, but the panic and money that has to be spent on mitigation measures. Now a CBNR device smuggled into the US would have even greater economic impact. The biological would be the largest potential threat. Radiological wouldnt be too bad but would scare the crap out of people and cost of a lot of money on decontamination.
A strong policy is to be level headed and don't overreact. It does no one any good just to ignore gaps in security.