Most of the big off-the-shelf engines (Unreal/Unity/CryTek/Source) do. If you look at first-party engines, though (Square Enix has Crystal Tools, EA has Frostbite, Monolith has LithTech, Activision has their IW engine for the CoD games), they're likely to be DirectX and console targeting. Valve is giving those kinds of engines the capability of targeting OpenGL through their existing DirectX support.