We'll see how much home console exclusives come for Japanese audiences this gen but given how much more affordable it is and how much more marketshare it should have...I'll say it'll slightly outdo PS3

6.5m since the Japanese console market is shrinking.

Id say about 8 million. General trend is Sony console sales in Japan are less with each new gen.
PS3 sold about 10mill so in any case im sure PS4 will sell less than that.

I think 8 million or it can reach 10 million in its lifetime but Japanese gamers have and will always prefer handheld gaming. It's been proven already with all the previous generations. That's a fact. Nintendo will always rule as long as there is a Pokemon game.

so it's already passed a million, many japanese games coming out, big japanese games i might add

I say 7-8m lifetime.

It'll keep selling like crap until they get some exclusives, so right now we really have no idea. If I was to just throw a number up there though, I'd say 15m.

So let's say it manages to sell 80K units per week (average) that's 320K consoles per month, so yearly we should have ~4 million consoles per year, so in two years it should have 9 million units sold.. Any possibility of this happening?

wont pass ps3.

Are you measuring the Japanese in yen? 

EDIT:

:P