But to qualify as an Apple Retina Display the new iPad does not require the same ppi as the iPhone 4 Retina Display because it is typically held further away from the eye, whose visual sharpness is based on angular resolution rather than the linear ppi resolution on the display. (displaymate.com)
The screen shares the same 300 ppi resolution as the Voyage and Paperwhite. (mobilesyrup.com)
That's a 207 ppi resolution over the RT's 146 ppi effort. (pocket-lint.com)