While the hardware is really similar, the software, controller, operating systems and way you interact with the consoles are the big differences.
I have Kinect now. And it's more than just neat, it's useful, helpful and now what I expect as the norm. When I was at my friends house last year, and she told me to find a specific thing to we were going to stream on her Roko while she set up our food. I was surprise how normal I felt to talk to my console. Egads, not with the Roku, I actually had to look at the little remote, type in (which is awful on the remote) in each app until I found where we could watch it. It was tedious and annoying.
Not being able to talk to your TV/Console was already 'in the past' for me. Like using a typewriter, why do that when you have a word processor? There is no joy in retyping an entire page, when you can just fix your error and re print it. It seemed antiquated and a bit barbaric.
If Microsoft can really pull this new Natural User Interface off they have been working on, it will really be something. The New Xbox One is part of that. If works like it has been shown, it will be as big or bigger than the creation of Graphical User Interfaces like Windows (First by Xerox, by the way.) And that computer in the movie Iron Man will be closer to the reality for everyone, not just billionaires.
The relentless arguing over hardware, especially from people with a very limited understanding of programming, seems like all they have. Few of us hear have even played a game on next gen, fewer still both. I don’t know anyone that can play hardware.
We are witnessing the evolution of a new interaction system. Arguing against innovation, reminds me of the people screaming about the combustion engine should not be allowed because it might scare the horses. How often now do we see horses on roads? And I have never seen one of the freeways.