Temple Ugrad and Temple Law '09 here. I would not live in the area immediately surrounding campus, but I also wouldn't be concerned at all about ATTENDING school in North Philly. Temple does have the third largest police force in Pennsylvania, and the Temple cops are great--willing to escort folks to their cars, etc. I never felt unsafe at Temple as a ugrad.
Folks are listing lots of good neighborhods in Philly. If you a little older (like me) or you like it on the quiet side, there are many communities in the burbs along the regional rail lines that'll do, too. I'll likely stay in lower bucks while attending Temple, but I'm already comfortable and settled here.