Fire Emblem usually sells about 50/50 between Japan and the West. Hype seems to be a little bigger around this entry though, so it's safe to say it will be the first entry in the franchise to reach a million sales. It will be out long enough this to barely make it this year, but sales will crawl by that time.
It's just not that big of franchise, and being optimistic it will reach 1.3m lifetime. I predict 1.0m.