That's correct. I remember several discussions at the UBIboards, refering to the statement of OpenGL being used for SoW and the doubts and fears connected to that. Somebody stated, that SoW will look photorealistic at highest settings, even considering the routines already implemented.
It was stated that all effects of the DirectX-Engine are possible with OpenGL, too, and lets not forget that Eyecandy-Games like Doom3 or ETQW use OpenGL, too.
Considering the experience Maddox Games has with OpenGL, I expect some very nice eyecandy in BoB.