Muncy is a beautiful little town; I highly suggest a visit just to walk the streets. Fall is stunning, and the view from the hills south of town is really something. Known for having more churches than bars. It's about a mile + in diameter. The downtown is pretty much a crossroads with a few stores and restaurants - stop in at Orlando's if you have a chance. Be warned, what there is, closes early. The school is, i'd say, better than average. The folks are very kind and community is strong, especially if you get involved in one of the aformentioned churches.
Lycoming Valley Mall, with most of your big boxes including Best Buy, Sam's Club and Borders, is a few miles northwest. Another 5 gets you to Wal-mart and Lowes. Closest supermarket is a mile east of town. Lots of nice old houses. Easy access to Williamsport and points south via I-180, which you can jump on right outside of town. 10 minutes south to I-80.
The job market...? Improved siginificantly since I lived there, although I think tech is still far behind. There are several industrial parks within an easy driving distance. The closest "city" is Williamsport, about 15-20 minutes northwest, which does have a fairly trendy downtown area and a few small colleges, if that's your thing (see also Bucknell, in Lewisburg to the south, 20 miles). IMHO, the area is just a little too small and the population a little too dispersed to create the critical mass necessary for a good business environment. It's just far enough from real business centers to make it difficult for startups to cheaply acquire the resources and connections they need to grow, and the airport is too small to serve as an economically feasable transportation link. It's moving in the right direction, if slowly. You'd do well to explore the job market thoroughly before making a decision.
Muncy is not a racially diverse place. For its size and ruralness, the education level of its residents is pretty impressive. Economically, the spread is quite wide, with the majority of families probably falling in the middle to lower-middle class. Violent crime is a non-issue. There's the occasional robbery, but that's usually a drifter- or wayward-youth-related event.
If you do intend to buy a house in town, I advise you look on the south side, as the north side (pretty much from the aptly named Water street north) is on a flood plain. Although you can probably pick up a nice victorian era home there for under $100K, having lived through a flood or two as a kid, I can tell you it's a lot of work.
Here are a few links for you:
http://www.lyco.org/lyco/site/default.asp (broken link)
http://www.muncyborough.org/index.html
http://www.muncyhistoricalsociety.org/index.html
Hope this was helpful!