Apple's iPad mini 4 is rumored to release as early as April or June alongside the iPad Pro, but if tradition holds, we might not see the smaller iPad until October or November.
Apple has so far enjoyed success with the mini line of iPads, including last October's iPad mini 3, but the fact that the mini 3 was almost identical to the iPad mini 2 (except for the addition of Touch ID and a gold color option) turned many dedicated Apple fans off on making their yearly upgrade.
Interestingly enough, at last year's Apple event, marketing head Phil Schiller gave very little attention to the iPad mini 3, showing only two slides of the new product to give more time to the iPad Air 2's limelight.
So from here, speculation can go in two very different directions: either Apple didn't trump up the iPad mini 3 (and therefore, the iPad mini 4) because they're phasing the line out as the iPhone gets bigger, or they didn't want to bring too much attention to the fact that the iPad mini 3 is relatively unchanged, and instead, focus on this year's iPad mini 4 as a new product.
Either way, there's not much concrete information out on the iPad mini 4 just yet. Hardware specs are rumored to include the same A8X processor that's in the iPad Air 2 as the entire product will enjoy a slimming down. If Apple is willing to make a new product and number identification for the simple addition of Touch ID, then it will certainly do the same for the bump up to the much more powerful A8 chip.
The iPad mini 4 is also supposed to get another feature from the iPad Air 2: anti-reflective coating on the laminated screen. The size of that screen, however, is still up for debate. If Apple goes bigger that the mini 3's 7.9-inch display, then the product starts to encroach in on the regular line of iPads, but if it goes smaller, it will directly compete with the 5.5-inch iPhone 6 Plus (and rumored 5.5-inch iPod Touch 6).
Other specs are a given, such as Retina Display, Touch ID, Apple Pay integration, and at least 2 GB of RAM, but Apple could also have something up its sleeve to introduce with the new product.
If Apple does decide to reinvigorate the iPad mini line, some speculate that the company will drop the original iPad mini and the iPad mini 3 altogether to leave only the iPad mini 2 and iPad mini 4 since it should include the Touch ID sensor that was the only thing defining the iPad mini 3 in the first place. That might leave some gaps in the numbers, but it makes business sense.
As for release date, if you take a look at every single other iPad mini, they were all announced in October and released in November (except the iPad mini 3 which was launched in late October last year). So if tradition is any indication, we can comfortably expect the iPad mini 4 to be announced this October and released shortly thereafter.
But a report from MacWorld speculates that the company may surprise us all by showing off the iPad mini 4 in April right along with the also-rumored iPad Pro. The Ipad Pro is supposed to focus more on performance and power, to compliment the iPad Air 2's focus on portability, so it's a very real possibility that the iPad mini 4 (also very portable) would be worked in to contrast the iPad Pro.
The iPad mini 4 is expected to retail for $399 on the wi-fi version and $529 for the cellular version.