All of the employees that work in NJ and live in PA pay PA tax...I will double check.
One minor detail to keep in mind - there is no toll on the I-95 bridge across the Delaware north of Trenton. So if you can line up your home and commute to use that bridge, that can save you a few bucks each month.
Well, I live in NY and work in NJ, and pay the full NJ state income tax on my earned income.