The fifth-generation Apple iPad might play an important role in iOS history. As we pointed out on Sunday, a source is spreading the word that the tablet will be offered in a 128GB variant, the first time we've seen that much native storage from an iOS device. Considering the lack of a microSD slot on the iPad, power users should be happy to have this option. If Apple codes the amount of storage on its mobile devices as GOOD, BETTER and BEST, the ULTIMATE that will purportedly be available for the new iPad SKU would certainly suggest a 128GB version of the tablet. The only problem with this theory is that the source of this story says that the next full sized Apple tablet will have no design change compared to the fourth-generation tablet already out. That would seem to go against the existence of a thinner back panel.
There could be a logical answer. Earlier speculation called for the next full sized iPad to launch in March. Perhaps that is when we will see a "Refresh" version of the fourth-generation Apple iPad with 128GB storage with the newly-designed, thinner version of the fifth-generation Apple iPad to launch in October.
source: 9to5Mac via GSMArena