Panasonic has announced that they are developing OLEDs together with Sumitomo. They aim to make 40" (or bigger) TVs by 2010. Back in 2008, Sumitomo announced plans for OLED TVs by 2009, and were seeking partners for doing it.
Panasonic also said they are partnering with other companies, but they didn't name any of them. There are rumors that one of these companies is Toshiba.