Things to consider:

PS3 sales for MW2 > 360 in the EMEAA countries. Black Ops is highly likely to repeat that performance. Americas is where MW2 sales on 360 takes a massive lead.

Halo: Reach, at least in the short term, is likely to knock some of the wind out of the sails of Black Ops, so the momentum on PS3 could be stronger. So the potential is there for the PS3>360 gap in EMEAA to be significantly larger than it is currently for MW2.

Pre-orders for PS3 Americas for Black Ops are looking strong relative to PS3 MW2 pre-orders. So the PS3 < 360 gap in Americas looks like it will be a lot smaller than it is currently for MW2.

Japan wil of course favour PS3, but the sales of each will be pretty low and not really play much part in overall WW sales.

So can the Japan+EMEAA gap in favour of PS3 end up being larger than the Americas gap in favour of 360 to give PS3 the overall WW higher sales?

I think, looking at Americas pre-orders for PS3 and 360, despite PS3 growth the gap in Americas will be too big for the rest of the world to completely negate it.

i agree for the 360 Americas BO sales will likely be too high to be negated. The gap could come down to 1mil when all is said and done though, but I very much think this will be the best selling ps3 game.

I highly doubt it... Although nothing is impossible I suppose.

99% chance that 360 version > PS3 version. Simply because of the US

If there were ever a year for the PS3 version to take it this would be it, but I honestly don't think Halo launching will knock CoD down too much.  Remember that Halo 3 and CoD 4 launched along side each other, and both turned out just fine.

PS3 version will sell tons, but overall 360 still wins...

Black Ops will sell more on 360 no question.

However, I think Medal of Honor may just sell more on the PS3 for a few reasons..

1. Pre-Orders in America are very close and in the end I don't think there'll be a huge gap in sales there.

2. PS3 owners in Europe/Others are more likely to pick up Medal of Honor because 360 owners already have two big shooters in Black Ops and Halo: Reach.

3. Sony and EA have a strong relationship and I have a feeling Medal of Honor will be pushed as a PS3 title in Europe/Others. For example Sony are releasing brand new gaming headphones in October to coincide with the launch of Medal of Honor.

 http://presscentre.sony.eu/content/detail.aspx?ReleaseID=6094&NewsAreaId=2 

You get the game free when you buy the headphones. While that alone won't push massive numbers, it shows that Sony and EA have a partnership for Medal of Honor in Europe which will likely determine which version of the game sells more.

This is interesting to me only because of the Halo: Reach factor. Oooo that sounds official!

Anyways, I wonder how much steam Halo: Reach will knock out of CoD:BO for the 360. I don't think the PS3 has any huge shooters coming out near this time; correct me if I'm wrong.

I know there are people who say that the crossover audience isn't that large, or that people will just buy both games, but you have to admit there will at least be some unknown amount of people who choose to buy Halo: Reach and skip CoD:BO on the 360. How many people it is will determine the outcome of this battle.

I honestly think it will be close!

What is the current sales difference between the 360 and PS3 version of MW2?

BO might sell more on ps3 if halo fans ignore call of duty.

Not going happen and this is coming from a PS3 fan. COD is too ingrained on 360, no matter how much Halos you throw its way

It definitely will... IN BIZARRO WORLD!

Not a chance.

nah, in EMEAA it might but NA 360 has double the install base....if ps3 COD:BO comes close to 360 sales in NA like the recent madden then that would be WTF. It's like FF13 selling more on 360 in JAPAN.