Known values for blending modes are (From LuminicBox):
MovieClip.BlendModeType.NORMAL MovieClip.BlendModeType.HARDLIGHT MovieClip.BlendModeType.OVERLAY MovieClip.BlendModeType.ALPHA MovieClip.BlendModeType.INVERT MovieClip.BlendModeType.SUBTRACT MovieClip.BlendModeType.ADD MovieClip.BlendModeType.DIFFERENCE MovieClip.BlendModeType.DARKEN MovieClip.BlendModeType.LIGHTEN MovieClip.BlendModeType.SCREEN MovieClip.BlendModeType.MULTIPLY MovieClip.BlendModeType.LAYER