Currently dxwrapper enables SSAA on NVIDIA cards when antialiasing is forced in order to get better quality. Unfortunately Intel and AMD cards do not have this hack, but they do have one for enabling ATOC which should help clean up most aliasing issues with transparent textures.

I tried implementing this myself (in the same way that SSAA is enabled) but certain graphical effects seemed to break, so it might be necessary to selectively enable/disable this.