In America, no doubt.

It could very well do so in the first month... America only though. Unless the European bundles for those games become immensely popular.

The Xbox 360 does have a ~50% userbase size advantage in the western world over the PS3. Add to that the fact that Halo is probably the 1st/2nd biggest name in console FPS games (depends who you ask and it can go either way depending on the day), reasonable sales of some RTS games in the past which should lead to some decent if not great sales.

Killzone 2 is dark, lacking in local play and the controls may be subjective to a lot of less experienced gamers and even many experienced gamers. It doesn't seem that they designed the game to be liked by the widest of demographics. People who need glasses hate dark games in my experience, people do talk and share their experiences with games and Co-Op is an important part of this, and games must be accessible otherwise the other good in the game will go completely unappreciated.

I say its definately possible!

Yes, Halo Wars will sell more in the first two months. The biggest factor for this will be the amount of hardcore Halo fans there are in the US, and the amount of xboxs there are in the US, compared to all the playstation 3's in Europe and us European's tendecy to sit on our asses and not buy ace games for a month or two after they come out.

Halo Wars first week sales might be double the Killzone 2 first week sales.

Just considering userbase, I feel that if the multiplayer in halo wars catches fire then it will definitely outsell kz2 and have longer legs, otherwise, it will initially just outsell it.

I would be completely and utterly shocked if Killzone 2 outsold Halo Wars in any region other than Japan.

Age of Empires 3 sold pretty well in Japan actually!

But FPS on the PS3 have found a pretty good home. R2, R1, and CoD 4 all sold over 100k.

Nope. Why would I be? We're speaking of consoles here Lafiel. 

it possibly could!