I would just like to add that I recently reread an article by Professor Hogg in which he said that during the time preceding the reference on Parliament's jurisdiction with respect to the upper chamber, a number of constitutional experts had testified before a parliamentary committee saying that the federal Parliament could take unilateral action without any doubt, and that, in the end, the Supreme Court of Canada said they were wrong. So there you have it.
On April 30th, 2008. See this statement in context.