MacRumors claims to have obtained an iPad 3 screen, and after putting it under a microscope, determined that the iPad 3 display's pixels appear to be one-quarter the size of those on the iPad 2.
Those who are good at math would know that by doubling the iPad 2's resolution in both directions, you'd see an increase of 4x in the number of pixels overall. Of course, this new "retina display" has been rumored for months.
However, as noted by display expert Raymond Soneira, Apple's claims of a iPhone 4 "retina display," one that is beyond the limit of the human retina to differentiate are faux. It wasn't even close, according to Soneira.
The claims, he said, made for good "marketing puffery," however.