Another possibility y'all are missing is that a high dollar could spur manufacturers to become alot more efficient.
During the last bout of US dollar strength in the 90s, Caterpillar decided to take a stand. The CEO at the time decded that they would implement every cost-cutting initiative that made sense. They enlisted the help of everyone in the company, all the way down to the janitorial staff, to root out every kind of waste. In other words, they got creative, then got busy trying to keep their jobs.
Why can't canadian manufacturers do this? We have alot of very capable people here. What we lack, and I'm very solid in my conviction on this, is good courageous management. It is management's task to lead their company. The easy way out is just giving up, and going offshore.
CAT didn't do that, and now they're a great american manufacturing success story.