t doesn't even have to be an avian flu- a normal, "human" strain could mutate and turn into a monster.
That is very true. The most likely scenerio is that someone will be infected with strains of both normal and avian flu at the same time. In such a situation the two viruses could swap some DNA and make an offspring with all the fatal aspects of bird flu with the quick person-to-person transmission of regular flu.
That's when things turn ugly fast.
-Blast