I don't think PS4 will sell more than the PS2, the reason is obvious. PS4 will have a short life cycle according to developers, and although the average selling is better than PS2, time is the main enemy. I would be happy to be proved wrong, but for now i think so.

PS2 isn't only cause it didn't have a world wide release. I remember the PS2 released 6 months earlier in Japan

But why 70m in NA and EU? No indication for that yet. I think it can manage it from RW though, but no indication it will outsell the PS2 as of now.

PS4 in 8 month have sold 3,750,000 in NA.

PS3 have sold 3,580,000 World Wide in 8 month.

If PS3 have sold 83,000,000 in one generaztion (probabily 90,000,000 in 2/3 year), Why PS4 don't sell 70,000,000 in NA?

No dont think so. PS4 will finish above every other PS console though.

Never going to happen. Part of the reason why PS2 was so successful was because it was introducing a new medium to mainstream audiences (DVD). Many people bought a PS2 specifically for a DVD player. I know I was one of them. I purchased a few games for it but I think I played a total of 2 hours of games on my PS2 for the last couple years I had it. It was a glorified DVD player for myself and a lot of other people.

PS4 can hope to sell around 100 million lifetime. Sales in Japan will be lucky to be half of what the PS2 Japanese sales were and it will be for NA with Xbox One all generation.

Well who's been there already has a better chance. The King may have returned in the form of PS4. Let the good software do its job!

No. I'm sorry. There really isn't much chance of that happening. PS4's sales are eventually going to slow down (quite a bit), no system can maintain 100k+ weekly sales. Part of PS2's situation was that it was a (at the time) relatively cheap dvd player, it benefited from the fad (ie played by more than just hardcore fans) of GTAIII, and ultimately it stayed on the market way past it's due date, simply because the PS3 was so slow to get off the ground.

I don't think, in today's market, that PS4 has any realistic chance of outselling PS1, let alone PS2.

I don't think it works out that way. The Wii changed the demographics of last gen, many hardcore gamers held out or bought a Wii and that didn't deliver. Also XBox  is still in the mix. We have no idea how the this gen will pan out but it's definitely not a linear correlation as you make it out to be. Look at the Wii. Fastest selling console after 3 years, and then died out quick.

Also apart from the fact the PS2 was a DVD player, it had ALLLLL the big exclusives from third parties. Doesn't happen anymore