Sources in the component world are speculating that Apple is working on the next iPad already with OLED displays aiming for a 2011 launch (obvious.) With the growing investment in world market on OLED technology the bet for future is clear. OLED displays have their own disadvantages but they are much better in performance when compared to LCDs. Apples adoption of OLED can act as a shot in the arm for the invested companies in this field and this makes me suspicious of these rumors!
While OLED can give rich experience in media, Apple would face challenge of more battery drain, visibility in bright light and increased cost. Logically thinking its too early for us to start speculating the iPad 2nd generation, as I am sure Apple would be taking feedback on the original iPad and then sketch out the map for future iterations of the iPad. Digitimes own estimates show that a 9.7″ OLED would shoot the cost of display alone to $500 which is currently the price for a base model iPad.
The current iPads use an IPS display which gives a better viewing angle (178 degrees.) And if all things go well, that is the technology Apple would stick with. Another promising opportunity is with the PixelQI technology that Notion Ink has taped.