We’ve been covering iPad 2 rumors and predictions here at BSN extensively and will continue to do so. That said, no alleged feature has stirred such a heated debate as the gizmo’s purported ultra-hires display.

A number of credible publications have been calling for the Retina display on iPad 2, from Engadget’s editor-in-chief Joshua Topolsky to fan sites like MacRumors and MacStories.

On the other hand, pundits like Daring Fireball’s John Gruber point out that a 2048 by 1536 pixel resolution on a 9.7-inch tablet would all but match that of Apple’s flagship 27-inch iMac which tops out at 2560 by 1440 pixels.

Display that dense wouldn’t just be cost prohibitive, Gruber argued, but the technology to mass produce it isn’t there yet. Plugged-in sources seem to agree with this notion.

Tom Mainelli, an analyst with IDC, revealed in an interview with PC World that industry sources told him Apple ordered that component suppliers develop a 2048 by 1536 pixel resolution display – but for a third-generation iPad, not the forthcoming iPad 2 which is expected in April:

Our sources say Apple has requested that manufacturers begin work on displays with that resolution for the iPad 3. I don’t believe anybody is ready to produce that resolution in volumes at this point.

And Apple is going to require huge volumes for the iPad 2.

Mainelli’s thinking contradicts a last week piece from Taiwanese trade publication Digitimes quoting unnamed sources from Apple’s supply chain who say the Cupertino gadget maker is adamant to up the iPad’s resolution significantly.

There also seems to be a confusion regarding naming conventions. Would a 2048 by 1536 iPad display be worthy of the Retina moniker just because it quadrupled the 1024 by 768 pixel resolution on the original iPad? 

Hasn’t the iPhone 4 with its 960 by 640 pixel display effectively quadrupled the number of pixels found on the original iPhone’s 320 by 480 display?

Apple says the Retina moniker denotes a certain pixel density, not the resolution. It means, Steve Jobs said at WWDC 2010, that your eye is unable to distinguish the pixels when you stare at the iPhone 4′s 3.5-inch, 326 pixels-per-inch display at a few inches away.

But simply quadrupling the iPad’s resolution doesn’t mean you’re getting the same pixel density. The 9.7-inch tablet has a much larger display than iPhone 4 and you sure aren’t holding it at the same distance as your phone. As a result, even a 2048 by 1536 iPad display probably won’t yield the same sharpness and crispness as the Retina display on the iPhone 4, although we have no doubt Apple will slap the Retina moniker on such a device for marketing purposes.