I don't know why people think that it isn't possible for PS4 to beat PS3. There is no real competition for Playstation this generation (this also means PS4 will have all the great third-party support => maybe Monster Hunter or Youkai Watch?). And as of now PS4 also sold better than PS3. And PS4 hasn't even got the big games yet (Final Fantasy XV, Final Fantasy VII Remake, Kingdom Hearts 3, Dragon Quest XI...). As of now it is very hard to tell how much PS4 will end lifetime. I think something between 8-12M seems like a safe bet.

Most reasonable thing said in this intire thread.

Well at this moment their is no proof that it will be certain that PS4 will beat PS3 or that PS4 will not beat PS3 LTD sales.

I find it hard to say that PS4 is doing great, if PS2 sold 40K a week people would create articles how PS2 is dying because at average the PS2 was selling in one week what PS4 sells in a month. Ofcourse time changes but even compared to PS3 it is not doing that great, the PS3 had everything against it, the Wii was selling amazingly and got exclusives announced on a weekly basis, the Xbox 360 was catching games that PS3 did not get or later...And ofcourse the price..

The PS4 has all the exclusives/competition is weak but still it did not beat the WiiU yet in LTD sales while many predicted it would outsell the WiiU in no time and the price for the PS4 is cheap compared to PS3...

Also we see a decline in some franchises on PS4, MGSV did not so good compared to MGSIV and MGSV was an exclusive in Japan so the potential 4000 sales on Xbox one could not have hurt it, Street fighter V released as an exclusive in Japan compared to SFIV and barely outsold the Xbox 360 first week in Japan of SFIV.. Star ocean V pre orders on PS4 are not doing that great and has the potential to sell less than the Xbox 360 version of SOIV in Japan... Really if someone made a thread two months ago will SOV in Japan for PS4 sell more than SOIV on Xbox 360 FW I would have posted yes like probably 98% of the users on VGCHARTZ. Is it because those games are bad? Is it because the mobile market keeping gamers away from PS4? Is it the average age gamers demographic in Japan getting smaller?    

Well, if it continues to get a good stream of games, I suppose it is possible, and it's not replaced any time soon.

Because the PS4 is considerably cheaper than the PS3, has no competition with Wii, and is tracking considerablly lower than every other gen leading console. 

Until the bigger releases come out, I'm not sure.

Considering how PS4 is only about 2.5 years in its life, I think it's possible.

I accounted for that already. You didn't point out anything.

I Think that it sell more than 1.2-1.3 Millions per year, and now is with a YOY Growth, and this year will have 2 of Japan's Biggest franchises out, Final Fantasy, and Dragon Quest, so of course will atleast surpass Playstation 3, Japan is the Second biggest country for Home console,  only Behind USA, even if it falls 50% of what it is now, would still be the Second Biggest for the Home Console Market, nearly the same as of Germany.

I dont, and I don't think those games will matter.

Metal Gear Solid V, is the best selling, or the second best selling Playstation 4 game of Japan, so the game did pretty well, Metal Gear Solid 4, wasn't a continuation of Metal Gear 2 ?, so this is the Main series, the 5 Isn't the continuation of the 3 ?,  is a Main release but is what Happens before Metal Gear 1, 2, and 4, and after the 3.

And also, Metal Gear Solid V, sold less on all the other regions of the World, isn't a Japan exclusive thing the game selling less.