I think three things are keeping the PS2 around longer than Sony initially intended:

1. This one's obvious--it's still selling really damn well.
2. PS3 isn't selling anywhere near the level of a typical Playstation-Brand product, and it's a massive moneysink for them. The reason they're removing BC from PS3 is so they can sell more PS2s for the time being and make some profit.
3. (And this one is really sad) it could easily live off all these terrible Wii/PS2 multiplat games for another couple of years.

What I think is great being a ps2 owner, is that you're still able to play some brand new game like COD5, TR underworld, rock band etc. So, you're still in the "fashion".

PS2 will proly stay strong till 2011.

PS2 is to be targetted at developing territories. For example they're about to start producing it in Brazil with at least three years of production planned. So PS2 should still be in production in 2012, and will quite possibly continue to be produced after that.

Can the ps2 make it to 200 million?

Sony have said the ps2 has shipped over 140million (this was back in E3).

200 I don't think so, but 150-160 is possible, and it would be huge. It it reaches 150M sony should organize a big party all over the world!

 It can't reach 200 million Kaz says the ps3 will outsell the ps2 at 150 million, if the ps2 wen't the 200 million then Kaz will have to start saying the PS3 will sell 210 million lol

I think it will see Xmas 09, the system is selling very nice numbers for it's age.

I don't think so