NEC Lighting developed transparent OLED lighting panels that use a transparent ITO film - and they plan to commercialize these panels by 2015. The company unveiled a prototype 20x20 cm panel that features 70% transmittance, 35 lm/W efficacy and 20,000 hours lifetime (not sure if that's LT70 or LT50). This panel was developed in collaboration with Japan's New Energy and Industrial Technology Organization (NEDO).