Two things I have been thinking about with regard to SARS.
1. Mortality rate is 4%. Some say it is higher. Even if it is 10%, that means 90 out of 100 people survive. Not something you want to catch but hardly a death sentence.
On the other hand,
2. It seems that today, most people do not believe a world wide epidemic is something that would or could happen. Of course, history would argue otherwise. Add to that our global mobility and one could easily imagine a repeat of the 14 century or 1919.
The hype sells newspapers, but the Media has, indeed, been crying 'wolf' far too much. The nature of Ebola, for example, demonstrates raging symptoms but flares up in such a way that prevents it from becoming more than a local epidemic. West Nile, on the other hand, is running more slowly and will definiely have a terrible, wide ranging effect on many animal species.