Let's just work this out.
From what I can tell the cost of high speed rail varies anywhere from $20 million to over $100 million per km. Let's go with $50M.
So it's what, 4500km from Vancouver to Montreal?
That's $225B dollars.
That would also give Canada the second largest high speed rail network in the world, China being the first (China also a has a lot more people).
What's a reasonable lifespan for this kind of system.. 50 years? Probably less, but lets say 50 years. So the rail system has to earn $4.5 billion per year to pay for itself in its lifespan (assuming no maintenance costs), or $12 million a day.
Lets say a one way ticket from Vancouver to Montreal costs $500, more than flying but lets say people will pay it. This assumes the maximum value per trip too, when most trips will be shorter and cost less, but again this is just best case scenario. At that rate, 25,000 people will have to ride the train every single day.
And I don't think a maglev type train is well suited for freight due to technology.
Yeah, I don't see this working on anything other than maybe a regional level.
EDIT: It's expensive enough you might as well take it out of the tax system over the next 50 years and give every Canadian a free lifetime ticket.
Interesting though:
http://en.wikipedia.org/wiki/High-speed_rail_in_China