The iPhone needs an unlimited data plan which Rogers/Fido do not offer. Fido used to offer unlimited before it got bought out by Rogers, 2-3 years ago. That's my guess why the iPhone won't be offered here till this important little detail is fixed. Other than that, I also believe the iPhone requires some system changes for visual voicemail that Rogers/Fido will need to implement on their system(s).
Now, I wonder, can I pick one iPhone up from the states if I am not a US resident???