Pork needs to reach an internal temperature of 160 degrees F (70 degrees C). While trichinosis, a parasitic illness caused by eating undercooked pork, is very rare, pork should be cooked to at least 144 degrees F (63 degrees C).
It used to be, in the old days, that pork had to be cooked through to as high as 190F. That is no longer true today thanks to the better conditions under which pig farming is conducted.
The FDA continues to recommend cooking food through before consumption - hence the frequent warnings you read in restaurant menus and such. However, you will see that many chefs continue to cook their pork chops until they're medium - and therefore not too tough to the bite. The difference in taste can be dramatic.