I haven't seen it mentioned yet, but there is an interesting phenomenon going on that those who live in the initial batch of countries for the XBoxOne, may not be aware of.
I live in one of those northern european countries that didn't belong to to the initial launch for the XBox. It was supposed to launch in April, but it is already available at all the major Electronics chains.
Not only is it available, but boxes are on retail shelves waiting to be handed to customers, with Microsoft promoposters and stuff up. The sales clerks caution that the menues aren't in our language yet, so most are assumed to use the English language version of the OS.
For those people who claim that a price drop will change the fortunes of the XBoxOne, I can contribute another observation. Since the PS4 is in such short supply, the retailers are jacking up their prices, so the XBoxes for sale are actually cheaper than the PS4. The boxes still aren't moving.
Summary - there is such a surplus of XBoxOnes that stock is redirected to territories that weren't supposed to have them yet. Due to the PS4 shortage, the XBoxOne are actually offered at a lower price to end customers than the PS4. The stock is still sitting on shelves - note that we are not talking about sales tailing off after the initial feeding frenzy, there is no initial feeding frency!
It's weird seeing sales clerks promote a system that isn't even supposed to be available, because they actually have systems to sell to customers, whereas the system that was launched three months ago is difficult to find at all. And still people aren't buing the new XBox. If I hadn't seen it I would never have guessed or predicted it.