I presume it'll work on any GSM network, therefore Rogers or Fido (they are the same anyway) will work.

Hopefully the 3G iPhone will be out in mid-June. Worst case scenario is to buy an iPhone in the USA, subscribe to a short term voice-only plan from Rogers while waiting for the official Canadian release later this year, and then switch onto that one...

From what I've heard, it takes about one week to become facile at typing on the iPhone...