I see no reason why EB won't have the GoW II demo, as they had the GoW demo available for anyone who pre-ordered the original game when it came out.
I'm hoping EB receives it sometime this week. I do know that quite a few of the new releases from last week were delayed to this week, so maybe that's why we don't have it yet.
I have the game preordered already, and my EB said they'd phone me as soon as the demo arrives.