Here's the number 23 bus, traveling on top of the tracks and below the power lines that used to serve the number 23 trolley, which stopped service in 1992. Here's the trolley, about 6 blocks north of the picture taken above (pic from Phillytrolley).
Trolley service is unlikely to be restored anytime soon, sadly. Plenty of people opposed to rail of all kinds trumpet the flexibility of buses over rail, rightly pointing out that it's much easier to add and change bus routes as desired. But there's a downside to that, as bus lines tend not to attract the kind of long term transit-oriented development precisely because there's no guarantee they'll be there forever.
But that state of affairs can be improve if the transit authority does make an effort to lay down some markers which show commitment to a bus line. One way to do this is to elevate certain bus routes, ones with especially high frequencies, over others, marking them as key routes. The 23 bus runs every 8 minutes or so during the day, giving it a frequency similar to the subways. Creating transit maps which graphically conveyed this information, highlighting certain trunk routes, would provide people with a quick sense of what more convenient routes were. Knowing that, people might actually choose to live in certain places due to the presence of the bus.
At least until they bring back the damn trolleys.