We have no idea how they got hold of one, but MacRumors has apparently sourced the display component for the next-gen iPad and put it under the microscope -- literally. In a deja vu moment from roughly two years ago when the iPhone 4 was confirmed to have a Retina Display, Mac Rumors put the alleged iPad 3 display under a microscope, counted up the pixels, and compared it to the existing display on the iPad 2.
Although the display was unpowered, microscopic examination still revealed the physical components of the pixels. When considering the same areal cross section of the display, the current iPad's LCD contains a grid of 2 x 2 pixels, 4 pixels total; this new display features a 4 x 4 grid for a total of 16 pixels. This much higher pixel density on the LCD, which is the same 9.7-inch diagonal size as the one on the iPad 2, is consistent with a display featuring exactly double the linear resolution of the existing iPad display.
In early 2011, various rumors pointed to the iPad 2 featuring a Retina Display upgrade; however, no actual parts featuring a 2048 x 1536 resolution ever surfaced, and the iPad 2 launched with the same 1024 x 768 resolution as its predecessor. The iPad 3 Retina Display rumors resurfaced this year, but this is the first time anyone has provided physical evidence of such a display.
The usual caveats apply: this display may be nothing more than a leaked prototype or even an extremely elaborate fake, and the iPad 3 may yet launch without a double-resolution Retina Display. However, at this point that scenario is looking unlikely indeed, and with MacRumors' new evidence, we consider the iPad 3's Retina Display all but confirmed now.