John McWhorther, Our Magnificent Bastard Tongue
In the South, you all or y'all is favored. Elsewhere in the country, you guys serves the same purpose, but without the charm. In Florida this winter I heard you guys much more than y'all. This could be because so many people in Florida are transplanted from elsewhere, but it could also mean that you guys is spreading. Even older women, who once hated to be referred to as you guys, now use the term themselves.
You might also hear you lot (common in Britain), you-uns, yinz (Pittsburgh area) or youse or youse guys.
We all tend to repeat the language we hear everyday, but I do hope Connie, who last I heard was serving a church in Virginia, is still saying you all, not you guys.