9to5Mac is reporting that Apple has plans to release a 128GB version of its fourth generation iPad. Not only have they received word indicating as much from trusted sources, but developers have also been finding data strings in the iOS 6.1 beta which point in that direction.
While it is certainly plausible that this new iPad model is the 128GB iPad, we are currently not confident enough to outright claim that, but it seems likely based on the evidence. [..]
The P101 and P103 names are Apple’s internal nomenclature for the WiFi-only and Cellular-compatible fourth-generation iPads, respectively. Both of those models comes in 16GB, 32GB, and 64GB configurations. These storage sizes are known as “GOOD,” “BETTER,” and “BEST,” respectively. As you can see in our table above, Apple is preparing to release the additional “ULTIMATE” model. “ULTIMATE” frequently refers to the most premium or highest capacity model available. The “A” points to a black configuration, and “B” stands for the white option.