I'm from Waterloo (RIM's hometown) so I'm biased, but there is a significant flow of Ontarians to Silicon Valley, Redmond and NY whereas there's no corresponding flow from the US to Ontario. So I'm tempted to call it a shortage of jobs rather than people.
Also from Waterloo, but I think you got this mixed up. There is an outflow of talent because there are only few exciting, innovative places to work in Waterloo. So sure, you can call it a shortage of jobs, but really the culprit is a lack of innovative/entrepreneurial/managerial expertise. Things are changing for the better, but slowly.
Also, it's goina be pretty hard to convince someone from Silicon Valley, NY (or even Redmond) to move to Southern Ontario, let alone Waterloo, unless your doing some really cool, or you can pay them a lot. Obviously people who go to school here are much more likely to stay, but even then, most of them would take a job in California if they had the chance.
