Man, I sure hope Philadelphia can bring a project like this to fruition.
It's already become a proven asset for Manhattan/NYC, and Philadelphia already has the needed infrastructure. We just need some cash, which can be a hard thing to come by in today's economy.
Here's an idea. Let Comcast pay for the whole thing and allow them to have all the advertising rights; what media company wouldn't want that. They already have so much cash that they're buying future Olympic rights (which has been known to lose money) because they don't know what to do with it all.
It could be called the "Comcast Line." I believe SEPTA made a few bucks off of AT&T when they allowed them to call the subway's stadium stop "AT&T Station," didn't they? Just imagine what kind of money could be made on this venture. The project would also bring insane amounts of development to this part of Philadelphia, just as it has in NYC.
Here's a great website to help educate you on the subject.