The singles scene is alive and well all over Charlotte, not just in a certain area. We have an unprecendented amount of Young Professionals and Professional social groups with no age limit. I am active in several, and have received emails from YP groups in larger cities than Charlotte asking my advice on how we got so successful! I would also agree with Groove that the best bet for you in CHOA (
Carolinas Outdoor Adventures - the largest and most active outdoor sport and social organization in Charlotte and greater Carolinas).
Most people here know that I have lived in the Ballantyne area, SouthPark, University area, Cabarrus County and Lake Norman in my years in Charlotte. I am younger (30ish) and single and think that people my age and ALL singles want a nice house for the money and they can get that in the Ballantyne area, as well as other "cookie cutter" areas. Ballantyne has Table, Jazz Cafe, Miro, and other great places. Music at Ballantyne Village, etc. For a night out, get a cab or drive uptown. Not everyone who is single wants to live in a 530 sq. ft. condo uptown just to be near bars, although that is an option for those who seek it.
Overall: this place is a great place to be if single. You can have a killer place to live and still afford to go out and taste all that Charlotte has to offer. It rocks to be single here. The fact I have been given the option to be relocated to DC, Orange County in CA, Philly and Miami and turned them all down to stay here as a single person says a lot.