I would have pre-order the game if I knew nobody in Canada was actually going to have the game in stock on their listed release date.
There was no incentive to pre-order the game (other than the Gamestop Xbox version bonus item, which IMNSHO was not a huge incentive). There was no special edition, no discount, no mousepad, no secret dragon slayer decoder ring....
Anyway, checking various Canadian sites, everyone stated there would be a couple day delay after the release before they would ship pre-orders. Now normally when a game is listed as being released on a certain date, it is in stores on or shortly after that date. The stores were not simply listing the official date, since it varied slightly from the 4th to the 7th, so presumably these were actual release dates.
Therefore, by pre-ordering, I would be delaying getting the game, compared to just walking into the store on the release date and picking one up. The marketing for DD wasn't that great, but I didn't have any trouble finding it on the release day.
I don't know if lack of pre-orders contributed to the delayed release, or if Canada is just an after-thought for the US publisher, but there probably would have been more pre-orders if it hadn't looked like there would be a penalty for doing so.