I'm no expert on the matter, but manufacturers of DVD and Bluray players do have to uphold to a certain standard to be allowed a licence to put a dvd player on the market. I remember hearing this was a reason why Nintendo didn't put in a DVD playback option with the Wii.
Same thing could be done with consoles.
That said, I think we are already at this situation you describe, if you look at some of the multiplats that get released. There are plenty of instances where a game has had a noticeably worse framerate on one console over another or worse loading times etc.