I spent quite a few hours in this airport between flights - on the side before the security gates, there's a Starbucks that's practically open 24 hours (sometimes it closes I hear).
Speaking of Starbucks, there are several locations on the secure side. Also on this side are shops and eateries galore, including local eateries I've never heard of like a tequila bar (Tequilerja).
There is a business center where you can rent a laptop or internet connection I believe, and there are conference rooms/halls upstairs. It's clean, bright, and sunny. Rocking chairs rock.
If I ever get stuck here again, I'm renting a car and hanging in Charlotte.