I'm currently working on a short spirit map pack, which will involve lots of stealth, including avoiding cameras, eliminating guards before they can activate an alarm, and avoiding being spotted. It's set in an installation in Siberia, which appears to just be a standard military camp, but has secret, illegal operations taking place underground.
I don't know how far I'll get with this pack, but if I get anywhere, I'll post some screens when it starts to show some promise.