I thought this was a pretty interesting read, covering what traditional DSLR companies are doing to develop their products, vs what new comers, and new technologies (mirrorless etc) are offering:
http://nofilmschool.com/2014/02/sony-alpha-a6000-mirrorless-canon-t5-dslr-price-cost/
It's obviously video biased, but I thought it interesting all the same.
It's pretty easy to argue for some features and not for others.
Overall for instance I don't care how many focus points there are as I typically use spot focus only.
(there is an argument that focussing and then recomposing may mean that the intended focus point is now not optimally in focus in it's new position in the lens field of view. the spot focus system only seems to work for me if you're doing stills work on a fixed tripod etc, but I digress).
Optical viewfinders are a plus for me, but the newer OLED offerings appear to have progressed dramatically over the traditional EVF's of the past. There's always an argument that you're seeing exactly what the end sensor is seeing too, rather than what the lens is offering before the mirror pops up. Maybe we're not there yet, but the tech is progressing.
The main focus for me though was to see the development of the latest entry Canon and to wonder exactly what has changed in it.
I guess when you're a major player like Canon then you're going to grab new comers to the game, who won't realise that the latest looks a lot like the latest from many years ago also...