Sure there might be more stuff, but come on, that wasn't just a picture release. That was a hands on impression article and most of the stuff described was cosmetic.
Thats because the easiest things to describe are the cosmetic things.
Infinite homescreens isnt a change to the core OS?
This:
Android 4.4 KitKat, in any case, it seems to be a version of Android much lightened
isn't a change to the core OS?
Hangouts replacing Messaging and getting SMS/MMS integration isnt a core OS change?
Lockscreen, Always Listening and possible Image Stabilization in the software aren't core OS features?
I'm not sure what you feel qualifies as a non cosmetic change then.