BioWare have just explained what's going on with the Mass Effect Collectors Edition and pre-order bonus disc. As in, which regions are getting them, and how they can get hold of them. As largely confirmed by EB Games' notices, in the US, you can get the CE only from "select online retailers". The game's bonus disc, though, will be available both online and in stores. In Europe, you can get the CE from stores, but the bonus disc isn't being made available. Australia won't get the CE (but will get the bonus pre-order disc) while Canada, well, you get fucked, and will be getting neither. Sorry.
New Limited Collector's Edition and Preorder Bonus Disc news [Mass Effect Forums, thanks Fraser!]