According to the industry source, if the next iPad mini uses Apple's current Retina display technology, it will have to have resolution of 2058 x 1536.That would work out to a pixel density of 326 ppi. The current version of the "byte-sized" tablet has resolution of 1024 x 768 for a pixel density of 162ppi. The Apple iPad mini is competing with the 7 inch Amazon Kindle Fire HD. That tablet features resolution of 1280 x 800 for a pixel density of 216ppi. Those are the same exact specs seen on another 7 inch Android challeger to the Apple iPad mini, the Google Nexus 7.
The same source had some news about the next version of the full sized Apple iPad. According to these insiders, Apple will decrease the number of LED light bars to one from two in order to decrease the weight of the tablet.