I have a few friends who got an iphone to play with at work. They were skeptical at first but came away believers. The biggest problem I have with the iphone in Canada, however, is the cost for the service. Much ink has been spilled on data rates in Canada. That alone will probably put a damper on everyone's enjoyment of the iphone north of the 49th.
In the USA, unlocking a cell phone for your own use on a different network is a
specific exemption to, I believe, the DMCA and is probably legal. In Canada, I'm not so sure. Plus, from what I understand, not all features on an unlocked iphone work properly at this time.