It looks like the iPad mini will get a worthy hardware update in 2015, unlike the prior model refresh which simply gained a Touch ID sensor. Resource files for the Safari browser in OS X El Capitan provide the clue, says 9to5 Mac, showing split screen views in the browser.
That suggests the iPad mini 4 -- assuming Apple sticks with its current naming convention -- will gain a processor comparable to at least the iPad Air 2, and possibly more memory.
Apple has previously said the split screen function in iOS 9 will only be fully supported on the iPad Air 2 which runs on the A8X processor and is the only Apple tablet with 2 GB of memory. For comparison, the current iPad mini uses an Apple A7 chip and 1 GB of RAM.
Some were disappointed when the iPad mini 3 launched last year with just a single hardware change from the prior model. I think, however, it tells us something about Apple's lifecycle plans for its smaller tablet.
By now, Apple fully realizes that the tablet refresh cycle isn't as short as the one for smartphones. Some people actually do get a new phone every 12 to 18 months, especially now that carrier contracts in the U.S. are finally dying off. That's not the case with tablets though, which can easily work well for several years.
It presents a dilemma of sorts for the company: How does Apple "wow" tablet buyers each year as expected?
The answer may be in advancing the larger, more expensive iPad each year but only giving the smaller iPad mini a worthy upgrade every other year. That strategy can help limit R&D and production costs for the smaller slate, which would boost margins on it since most components would decrease in price over time.