Since TLOU remastered came out on PS4 it hasn't dropped below 144K a week according to VG Chartz, so an increase of 36K per week would be needed, not that impossible IMO, I think China could add similar numbers to Japan's lowest point as a minimum, so about 5.6K a week, although the potential is there for a lot more than that. PS4 launches in China on the 11th of Jan and that should help out with early Jan because there aren't a tonne of new games launching until later in the month.
Maybe the beginning of Jan may be lower than 180K, after that I don't think it'll go below that.
Throughout the year the library will be growing a lot compared to what's been released this year, so that will no doubt increase the baseline after January.
Post China release I think 180K per week is probably a pretty fair minimum number for PS4 to sell, although I wouldn't be shocked if the baseline is higher than that.
Ratchet & Clank is meant to be coming out in the first half of 2015, Until Dawn is a summer release, Tearaway Unfolded could be a mid year release.
Uncharted 4 has placeholders for July 31st, so that could be an early Q3 release.
There are a lot of 3rd party releases, like Batman in the middle of the year. New buyers won't just look at a few games coming around when they want to buy the console, but the complete library they can get hold of on that system.
There will be more Japan focused releases throughout the year for that region too, so that will boost sales in Japan.
