Sharp is showing flexible 3.4" IGZO-based flexible touch OLED prototypes at CES. These panels seems to be the same ones shown at SID back in June 2012 - and if so they have a resolution of 540x960 (326 ppi).

Sharp wouldn't say whether they intend to start producing such panels, but they did say that they have the technology to produce such panels in sizes up to 10". They say the image quality and resolution is the same as in their non-flexible OLEDs.