9to5mac went digging through Apple's iOS 5 code and discovered a reference to an unreleased device codenamed "J2" grouped alongside other well-known codenames like N92 (CDMA iPhone 4) and K95 (iPad 2). While certainly still unconfirmed, this lends credence to a DigiTimes' report from a few weeks back that indicated Apple was testing two prototype tablets, codenamed J1 and J2, that run 2048 x 1536 displays (sound familiar?). That's four times the resolution of the current iPad, twice for each dimension, and the same relative upgrade the iPhone 4 received with its 'Retina' display.

CNET is adding more fuel to the fire with its interview of DisplaySearch analyst Richard Shim, who claims a high-resolution iPad is definitely happening, with three suppliers providing panels — Samsung, Sharp, and LG. This all falls strictly in the realm of speculation at this point, but one thing's for sure: we're going to hear a lot about the next iPad over the next few months.