A recent article in the Korea Times has stated that 2 of the biggest LCD manufacturers, Samsung & LG have been working closely with Apple to produce new 2048×1536 HD displays, with an aspect ratio of 4:3 for the iPad 3. The current iPad has a mere 1024×768 resolution display in comparison. This will mean the display on the iPad 3 will indeed be full HD. It is still unsure which of the 2 will win the big contract with Apple, or maybe Apple will use both to fill the, what is likely to be, HUGE demand for the next iPad.
This does however mean that the iPad 3 is most likely not going to get the OLED displays some sources have been claiming. I personally think this is a good thing, the quality and lifespan of an OLED screens still isnt up to standards of our current LCD screens.