I would lay huge money on it being in the US, the only Canadian city now is Toronto and with our " Not open for business " tax system I can not see it awarded here. I read an article this morning and Amazon said they are expecting huge breaks and some of the cities were offering the moon. With the new min wage in Ontario ( although it will not effect 99% of their employees ) high hydro rates, , business taxes and a carbon tax it will not happen.
Kind of sucks for Canada, even Calgary was in the running at the start.