No.

So, another "... just wait until... " game?

It won't make a long term difference, it's just one game. Right now the 360's momentum is 30% library 70% price. KZ2 can't change that momentum alone. Also, while it looks amazing, it's still going to have to review well. I haven't played a demo or a beta yet so I can't say, but I'm still skeptical of the games quality having played KZ1. I can say with some certainty that this game will have to review well for me to buy it.

How long do you believe the bump in sales by KZ2 would last, if it happens?  If you have KZ2 selling MAYBE more than Gears 1, how can you say it would end up being a game changer for the sales of PS3 vs 360?  How many sales were gained by Microsoft by the sale of the original Gears of War?

I would speculate it isn't that much.  I would also say people do a great disservice to the Playstation brand by holding up these overstretching expectations.  Such expectations come from people who are supporting a system that is losing console wars.  I saw it back in the Atari days when people held hope Tempest 2000 would be a game changer for the Jaguar.

With a price cut (even $50) yes with out... nahh unless GOW3 magically comes out in March.

The only game that will raise ps3 sales will be Gran turismo 5, but by the time it'll be released it's gonna be too late.

Not me, Sony should be happy if the game sells well.

As others said, maybe it can for a week or 2. However to constantly outsell it would need a price drop.

I think it will be pretty unlucky for them if they can't afford a price drop along with KZ2. Would hurt potential sales quite a bit.

I think people are overestimating Killzone 2. It all depends if the American market wants it or not. This isn't a MGS4 type big name here. I don't think that it'll be that big in sales. I see it doing Resistance 2 numbers.

Why does anyone expect Killzone 2 to sell that much, that it could stop the PS3's fall?
I think it will sell well, but not great at all. The hype is missing and Killzone is not a well known franchise.