Would seem like an ideal candidate for something like the high line on a grander scale. Given that it seems in decent shape,you could even have something like part of it is a walking trail kind of thing, like the high line, and use one of the rails for light rail, maybe an open trolley as a kind of tourist oriented thing...surprised no one has even proposed it yet. While I am not entirely happy with what the high line has done (I love the high line itself, but the area it is in has flipped too far the other way, instead of being interesting, it now is the high end realm of the 'beautiful' people and 'their' kind of restaurants and stores), the potential to make money off it is huge.