Most Canadian carriers activated the Personal Hotspot feature when it went live with the iOS 4.3 upgrade back in March. TELUS’ sub-brand Koodo Mobile was holding out for some reason (odd as all of their Android devices have a Hotspot features build-in)… but 3 months later it now seems that Koodo has flipped the switch and enabled this for their customers.
If you brought an iPhone over to Koodo you can check to see if it arrived for you via Settings > General > About.
Source: iPhone In Canada
