the direct 2d demo showed bezier curves being rendered at high framerates with antialiasing as part of the demonstration. I'm pretty sure it's to be used for vector stuffs. which won't necessarily help construct, especially since it probably won't be out any time soon, but I think down the line, it'll make it so vector graphic based games will become more prevalent. beziers and 2d polygons won't be so cpu intensive, and more complex vector graphics may become possible during gameplay.