I personally believe that this would be good for Canada. I believe that first-past-the-post becomes less effective the more legitimate parties that run in election.
By the way, BC tried this 2005, and it was narrowly defeated. They needed 60% support overall and 60% of the ridings to have a majority. They got the number of ridings (77 of 79), but just barely missed on the overall support (57.7%). I watched it, hoping for it to pass. See here:
http://en.wikipedia.org/wiki/British...rendum%2C_2005