I see a lot of people here doubt One could win worldwide, but why not ? I'd find that worrying if it cant even achieve that for this specific week, it would mean it's totally dead outside US and nothing could change that.
A price drop is a big event in term of sales, we should expect sales like 80k at least in US and 20k at the very least in Europe with Uk, with the rest of the world, it should easily outsell PS4 in poor week. ( 110k-120k )
Predictions for end of 2014 HW sales:
PS4: 17m XB1: 10m WiiU: 10m Vita: 10m