Look at this picture of a guy gored this year. Impressive!
Anyway, it isn't normally like that. Normally, the run is pretty clean, only a few injured because of falls.
BUT the running of the bulls is dangerous. If you go to Pamplona enjoy the rest of the festival (Fiesta), have fun, it's one of the best festivals in the world and watch the run on TV, like most of us, the locals, do.
For pretty pictures about the run and the festival have a look to this
link