What is the rational that US/UK is Xbox's?

[mutantsushi]

IMHO the OP's post loses cred when it writes: "360 barely squeaked out a win in US."
while the included chart shows a roughly ~50% lead, which is not "squeaking by".

Broadly, those types of statements amount to saying US/UK will be MS' strongest territories, which is true.
Unless one is to predict that MS will simply lose in ALL territories, you would expect a similar statement.
The sales to date are of course at the old Kinectless pricepoint, so at lesser price they guess MS can still win US/UK
if only "squeaking by" it seems a heavy possibility, enough to make sense of such predictions.
(Titanfall bundle "pseudo pricecut" didn't really show much effect, but it wasn't 100% transparent either)

Or else you can chalk it up to fluoride in the water, your choice...