The issue of hybrid cars and pedestrian safety has actually been in the news for a while now. Many major cities now mandate that all the licensed taxis be hybrids. With the increase in hybrids in cities (which by their nature have many more pedestrians), has come an increase in accidents-- especially incidences of blind pedestrians being struck. They tend to rely on listening for oncoming cars, so between the quietness of a hybrid and the background noise of the city, quite a few have been hit.
I've even seen close calls in parking lots where the pedestrian doesn't realize a car is even running (because the hybrid is sitting there silently), happens to walk behind it and suddenly the driver starts backing up.