I'll not go into an indepth argument here about why Canada would be well served by a change in the electoral process. I'll just post the numbers from this past election as I think they speak for themselves:
CON 124 36.25%
LIB 103 30.22%
BQ 51 10.48%
NDP 29 17.49%
IND 1 .52%
OTH 0 5.05%
Have a look at the BQ and NDP numbers. The BQ managed 51 seats on 10.48% of the national vote, whilst the NDP only pulled in 29 seats on their 17.49% of the popular vote. While this is an improvement for the NDP over last time around, it aptly demonstrates the advantage a single member plurality system gives to regionally concentrated interest groups. While I agree there should be regional interest representation in the Canadian political system, there should also be greater representation of groups spread across the Canadian map. Canada is oft plagued by regionalism which has threatened on numerous occasions to break up the federation. A shift in electoral system could help mitigate these regionalizing influences, while convincing people their votes are not wasted on "no hope" candidates.