The USDA has finally updated their guidelines for cooking pork, announcing that an internal temperature of 145 degrees F is quite sufficient for cooking pork.
It's well known that Trichinella is killed at 137 degrees F; I and many others have been saying for years that it is unnecessary to cook the living hell out of pork. Old cookbooks often advised people to cook pork to a temperature of 180 F, which makes it inedibly dry.
For me the issue with doneness of pork is a matter of texture. When I make a pork roast, I generally cook it to an internal temp of about 155 F or so. I find pork that is too rare to be uncomfortably "slimy" in mouthfeel. (That particular quality disgusts me; it's why I hate gumbo and many types of sashimi.)
So, Huzzah! to the FDA for this sensible new guideline!