I've tried to post a few times when I see them or know they're going up online. But I'd start with this:
http://www.nowinstock.net/ca/videoga...esclassicmini/
BestBuy have also given a heads up beforehand in this thread:
http://plug-in.bestbuy.ca/t5/Video-G...160842/page/56
Other sites like neogaf or redflagdeals will have threads with updates or news.