It looks like the earlier draft policy on open access for federal Tri-council funding in Canada has been made official. NSERC grants starting after May 1, 2015 will have to comply with the new policy. This seems similar to many other agencies, such as the NIH, which require access within 12 months of publication.
The “deposit elsewhere after publishing” model is usually referred to as “green” open access, and many journals now support this model after funding agencies have begun requiring it. This is usually a zero-cost option for the authors (which is a good thing.) “Gold” open access (where the authors pay a fee at the time of publication to allow immediate OA) costs grant money, and is not always an option when budgets are tight.
ACS journals allow users to deposit their work after 12 months in a repository, such as PubMedCentral, for NIH funded work. Presumably a similar policy will be developed for NSERC. RSC journals also allow OA archiving, as does Nature Publishing Group, Wiley, Elsevier, and others. Some of these (like Elsevier) are journal-specific, and may be worth reviewing before submitting a paper for review.