So Canada gets Rock Band a little late. Big whoop. The entire PAL market is also without the game, and don't even have the vaguest of dates to pin their collective hopes on. So quit your whining. To help you quit, you should know that because you're a little behind on the game's DLC, the Canadian Xbox Live marketplace will be playing catch-up, a Harmonix rep posting on the game's official forums:
As of today I am hearing that Microsoft plans on releasing the DLC in Canada on the 20th through the marketplace. I believe this will be a monster release of every song we've put out so far as DLC for the game.
Great! Except...hands up how many Canadians will actually have a copy by tomorrow? That's what we thought.
[Rock Band Forums, thanks Jaemeel]