Rumors are abound. Amazon and Bestbuy in the USA already threw stuff online while people were sleeping, which soldout instantly (15-20 minutes apparently).
EB Games may be taking in-store preorders when they open, and online at some time (check Twitter if you hope to get that).
Amazon.ca has a listing up with no stock:
Nintendo's product page suggests it will be available from Amazon Bestbuy and EB, and links to their front pages: