I doubt it has anything to do with exclusivity. It is probably just: "We have really cool stuff to show you and since the 360 is our bigger base we will show it at the MS conference."

could be exclusive DLC or timed exclusive game/DLC.

if this is MW2 exclusivity then it will match the FFXIII megaton and make them win E3 again by Ko

(sorta)

I hope it is not true

Is there an Activision Blizzard press conference?

It couldn't be exclusive. Thousands of PS3 pre-orders have already been made

Can you please leave and stop forcing you own brand of common sense onto people.
Everyone knows MS moneyhatted exclusivity.

At least thats what I keep hearing.

Well over there at IGN they have some news about 3 exclusive games to be announced by MS
As soon as the conference ends, we'll have exclusive previews of three of the biggest games shown during the press conference. Here's a hint: one was announced a while back, two are being announced at the show

http://xbox360.ign.com/articles/988/988140p1.html

What three could they be?

Nope

It looks like they have their own event, but why not cash in on the hype at E3 without having to pay for it? I am sure Microsoft is more than willing to give them time.

Confirmed,its not an exclusive.But still it cud be timed but even that wud not be possible cause wen orderinf a game,u r given a release date

Microsoft showed plenty of multiplatform games last E3. At best MS have got timed exclusive DLC.