To repeat what I said on a thread about the same subject:
It shouldn't be ignored that the current Canadian government has a pro-Israel, neocon bias unmatched even by the US government. The problem isn't so much Iran, but Canada's own ideological extremism. Under that Stephen Harper buffoon, Canada has become a caricature of what the US was under Bush, emulating and exaggerating the worst qualities of the US neocons' rhetoric.
Media analyses have pointed out throughout this week that Israel had lost face as the US, in repeated and increasingly tough statements, let it clear that it doesn't think Israel has what it takes to bury Iran's nuclear program. Canada's move, in my opinion, is but an attempt, one terribly exaggerated, to save face for Israel.
I find this move pretty pathetic. If it will leave anyone isolated, it will be Canada, not Iran, as I doubt any serious country will follow it in cutting ties with Iran just to appease Israel.