I get the feeling Killzone 3 will be to Killzone 2 what Uncharted 2 was to Uncharted, so put me down for 4 million.

Of course, I said the last one would hit 4 million as well.  =/

To be fair, I didn't expect things like controller lag to become such a big issue.  I didn't even notice the input lag when playing the beta.

< Killzone 2. I feel a lot of games sequels released in within the same gen dont do as well as the previous installments. Im not a fan of the series but I do hope Im wrong, those guys put a lot of work into the game. Unlike Uncharted 2 the market is flooded with FPS's and Im sure COD 8(9 or 10 or whatever) will still take peoples dollars.

I doubt that'll happen considering Killzone 2 had nearly zero advertising.

umm around 5 million by the end of the year

1.2 million forst week

around 4 million lifetime

I find that is generally the case, however it can be offset by noticeable improvements in a game's quality and/or improved marketing over its predecessor.

Devil May Cry 3, for example, outsold Devil May Cry 2 rather significantly last gen, and this can be attributed to the fact that DMC3 is the much better game between the two.  This gen, Modern Warfare 2 has outsold the original Modern Warfare handedly, as a result of Activision's significantly increased marketing for the sequel.

Uncharted 2 also outsold its predecessor handedly, a result of both noticeable improvements to the main game backed by a much improved marketing campaign.  Halo: Reach is also looking like it may top Halo 3, for similar reasons.  Same happened with Halo 2 over Halo.

By all accounts, Killzone 3 is looking to be a much better game than Killzone 2 (especially if it does end up having co-op), and on top of that it should be marketed better than Killzone 2, so I believe it should be able to enjoy an improvement in sales similar to the Uncharted franchise.

Since the ps3's uptake in sales post-Slim, Sony has really amped up the advertising for their first party releases, attempting to turn their more popular IPs into system sellers (seeing as they can no longer rely on third parties for such marquee titles).  They have done this with both Uncharted 2 and God of War III, and I have no doubt both LittleBigPlanet 2 and Killzone 3 will be marketed much better than their predecessors as well.  These alongside Gran Turismo are their five biggest IPs at the moment. 

Killzone in particular is SCE's flagship FPS franchise, and it's obvious they're trying to make it their own exclusive Halo/Call of Duty/Battlefield.  They're definitely going to try and make this one bigger than the last, though I admit it could fail to happen.

Killzone 2 having nearly zero advertising is load of horse crap.

In Europe, i agree.  They had like a red carpet reveal and ads on the sides of buildings over there.

In North America its marketing was fairly weak though, and most definitely ineffective.  One crappy tv ad that showed nothing of gameplay or anything exciting at all is not how you sell a game.

First Week :

NA - 1.0 Million  
EMEAA - 850k
Japan - 20k

Total = 1.8 - 1.9 Million

Lifetime :

NA - 2.6 Million
EMEAA - 2.4 Million
Japan - 35k

Total = 5 Million Lifetime

Killzone 3 is going to be full of suprises.

2.5M

I think KZ2 = KZ3 for the most part (sales wise)