would expect the mini to be always given lower specs than the big iPad to differentiate. There's been 3 iteration of iPad Mini and from the pattern, last year looks like the anomaly.
Yeah I never expected last year's retina Mini to have the full A7 and feature set from the full-sized Air. And I think Apple made a mistake releasing that model because it probably cannibalized the crap out of Air sales and it also raised people's expectations from that model when Apple seems to be happy leaving it as a second tier product rather than another flagship model. The mistake I think they made this year wasn't leaving the A7 in the iPad Mini 3, but in not lowering the price back to the $329 of the original Mini, or maybe $349. $399 is too high of a price if the internals are going to be a generation behind the $499 Air X models.
Anyway, having 5 tablet lineup is so not Apple. Simply too many to choose.
I think they are letting the gap come back between mini and iPad full. At one point, mini was a little weaker, but when Air came out, they made them matched specs. I think they are trying to bring back the gap where mini is a spec class behind full size again.
But with how lame people think the mini announcement was this year, they may not stick with that plan.
Next fall, no question. There will be no interim updates or new "pro" model before then. First half of the year will be all Apple Watch all the time. Apple will nothing to distract from its promotion as it's new product. Broadwell laptops will ship early summer to be ready for the school season. That takes us to the usual fall events.
With the addition of the iPhone 6+ put the iPad mini in a difficult position. It's that center product that can cannibalize two products the 6+ and the iPad. I think it was a mistake to come out with the mini w/o retina as it made it an inferior product compared to the competition. It will be interesting to see what apple's future is for the product. Personally I would much rather have a mini than the regular iPad because I think it has much better value and I like the smaller form factor, makes it much more easier to tote around for taking/editing pictures and video. Will be looking forward until next October to see what they do with it.