We're looking in to the possibility for the future but there are a bunch of complications that stem from the differences in how paint strokes are generated in ArtRage compared to simpler dab based systems, and additional ones relating to the natural media simulation and the limitations GL processing which is why we don't use it currently. Adding OpenGL support doesn't automatically speed anything up, it's just a tool that we may be able to use to accelerate some of the calculations that go on in the construction of strokes.
Matt
ArtRage UI
Ambient Design.