Please PLEASE try looking through at least the first page of the forum before posting stuff like this!
https://forums.macrumors.com/threads/1485305/
Same report but with the crucial additional bit of information that production isn't scheduled to ramp up until second half 2013.
And I'll say the same thing here that I said there, this isn't just a case of producing a different, less power hungry screen. Apple also need to deliver the equivalent power of at least the A5X (ideally the A6X) in an incredibly efficient SoC, something that's unlikely to happen by... well, by January actually if you want them to launch in the spring as production needs to ramp up well in advance of the launch date.
This is a guess but hopefully it's based on solid reasoning: Apple will effectively need the A7 to produce a retina iPad mini without compromising weight and size. Such a SoC would be likely to run on a 20nm process (most likely from TSMC) and feature Power VR Series 6 gpu's. The CPU is much harder to predict as Apple have now left, at least in part, the standard ARM roadmap but let's just assume it's the next gen on from the current A6, the equivalent of an A15 part but without some of the potential power issues that design may face.
Looking at the iPad 3 and 4 the big roadblock to delivering a retina display is graphics power with 4 GPU cores being required using current tech. It's not unreasonable to assume that Series 6 (which brings a potentially very big boost in performance) will reduce that considerably. For the sake of argument let's say a 2 core GPU will be the equivalent in raw power as the A6X is today. That raises a very interesting possibility across the iOS range.
A standard A7 (dual core CPU, dual core GPU) could easily be the flagship chip for iPhone and also run the iPad Mini with retina while also providing a noticeable real world performance boost over the current model. Apple could, theoretically, run the iPhone variant at an even lower clockspeeds than today to improve battery life and still see performance increases. Meanwhile an A7X with quad core GPU and maybe even quad core CPU would be achievable for the iPad if Apple didn't mind spending the additional die area to achieve it. That would give a very clear reason for going up to the larger device and effectively work in much the same way as the 13" and 15" rMBP spec does now - the bigger device can make use of that extra space and battery power to run a hotter, more power hungry system. Oh, and at the same time the current iPad Mini could be retained and dropped to say $249 the same way the iPod Touch line currently has the previous gen as the entry level device.
As I said, just a guess but it would tie up with most of the production rumours we're hearing at the moment and seem to make sense in a wider context of Apple's product lines and general narrative.