Alright, I am going to go a little nuts here and quote someone from another topic, it helps me justify why I don't think Apple should separate the 4.7 and 5.5 with specs.
-----------------------------------------------------
---Quote (Originally by cababah)---
A developer that makes an app that only works on one iOS device is not a wise developer. The more devices that can run their app, the more $ they make.
---End Quote---
True. I probably could have put my point across better by saying that eventually there will be apps that don't run on less than 2GB, and so there would be the situation where an app will only run on the 2014 Air, but not the 2014 Mini.
Similarly, one could imagine for example a game, that was designed such that it needs 2GB RAM to run its highest quality mode. This is not far fetched, as we are already seeing PC games from the not-too-distant past being ported to run on iOS (e.g. Bioshock). Therefore you would have the situation where your iPad Mini's performance was severely compromised through no reason other than lack of RAM.
And considering that RAM is pretty cheap now, I see no logical reason for Apple not to keep their iPhones and iPads as close to identical as they can, ignoring size. Varying things like RAM just fragments the product line, and unnecessarily complicates the production and supply chain.
-----------------------------------------------------
I really truly believe that the 4.7 and 5.5 should follow the iPad mini with Retina Display and iPad Air's footsteps, ignoring size, but keeping the same specs.
So, I am predicting that the 4.7 and 5.5 (if there even are 2 devices in the first place) will have the same, if not, very, very, close specs. Aside from battery though, the larger display obviously needs a larger battery to maintain the same battery life as the smaller device.
Less knowledgable people may feel cheated by Apple if they got the 2014 phone, but the other 2014 phone which seemingly is just bigger and more expensive (both factors are commonly less favorable among people) has more stuff than the phone of the same year, and potentially, name; iPhone 6.
Sorry if my explanation got... Convoluted. I have trouble organizing my thoughts at times, as many arise at once.