for $4.95/mo, Sprint roaming in Canada is $.20/min. I'm not sure what the price is without the roaming package. I used my TP all the time when I go there. This weekend, I am going back for the first time since getting my TP2. I still have my Rogers account (gotta love 3-year contracts!), so I intend to stick my Rogers SIM in the TP2, tell it to go GSM only, and see what happens. I am hoping it will work...
As an aside, though: one of the reasons I chose Sprint is the MASSIVE difference in data roaming charges when going to Canada. While VZW and ATT charge something like $14/MB, Sprint "only" charges $2/MB. On top of the simply unlimited plan not being matched by anybody, this was a major factor for me going with Sprint.
@pauldehoyos: Moosehead, huh? I'll have one for ya. That's from my neck of the woods