+1 on the pad change. Not sure I'd want to block any airflow from the discs anyway, they already can get really, really hot (can't they, Brad?).
I have no idea why Nissan chose the pads they did, although I look around town and see BMWs and Mercedes with blackened front alloys, so maybe they're trying to do what the upmarket brands do.
Personally I think the stock pads are crap. Heat fade is too common.