The new policy has good intentions to be sure - but will it actually lead to an increase in the accessibility of scientific publications, or will the publisher's copyright stipulations prevent this? A quick search of a few life science publisher's copyright policies reveals considerable variability in the freedoms they grant the original authors to share their research online:
Cell, Cancer Cell, etc. - Author cannot archive pre-print. Author can archive post-print on their own server given that the publisher is cited and linked to, but the publisher's print or PDF cannot be used.
Nature, Nature Medicine, Nature Genetics, etc. - Similar to Cell, but pre-print is allowed and there is a 6-month embargo before post-print archiving is allowed.
Cancer Research - Archiving not allowed. Except for NIH researchers, who can archive 12 months post-print. (Look to see if this exception is also granted to CIHR researchers in light of the new policy).
PLoS Biology, Medicine - Author may archive pre- and post-print under a Creative Commons Attribution License. No restrictions.
Journal of Biological Chemistry - Similar to Cell, but pre-print is allowed.
Blood - Similar to Cell, except Wellcome Trust (British funding agency) researchers may submit to the Biomed Central Repository for a fee.
As it is common practice for scientists to send copies of their articles back and forth and free of charge upon request, I don't see how any of these restrictions are justified; making your article available for download just makes the process more efficient, and makes it easier for non-academic members of the public to read about science with their own eyes.