Sharp-eyed visitors to Apple's Canadian website spotted this bit of verbiage on the iPad 2 3G page:
?If you decide on an iPad with Wi-Fi + 3G, be sure to select the model that corresponds with the carrier you‚Äôd like to use for 3G service. The iPad model you purchase is specially configured to work with either Bell, Rogers, or Telus. So while you don‚Äôt have to activate 3G service right away, you should choose your iPad with Wi-Fi + 3G according to the carrier you prefer.
So some digital Chicken Little went into "the sky is falling!" mode and declared that Canadian iPad 3G's would be carrier-locked, contrary to Apple's original modus operandi for the tablet (i.e. it wasn't locked to any one carrier, and would work with whoever you got your data plan and SIM card from.)
Let's drag out the Richard Nixon impersonation and make one thing perfectly clear: the vast majority of iPad 3G's are not, were not, and will not be carrier-locked. Not in the Great White North, not in the lower 48, not nowhere. Unlike the iPhone and its carrier-specific SIM — and the myriad of jailbreak and unlock exploits that followed — the iPad is "carrier agnostic." Both Rogers Wireless in Canada and AT&T in the US have confirmed this.
The Canadian misunderstanding arose because each carrier has slightly different software settings for 3G activation. Simply swapping SIM cards will not automatically update the settings over the air — for that, you need to sync to iTunes to obtain the new code.
One other caveat: Verizon iPad 3G's are, in fact, carrier-locked, due to the carrier technology (CDMA vs. GSM elsewhere in the world) and its SIM-less underlying hardware. You'll recall that the first wave of "vPads" required a mobile hotspot gizmo and accompanying data plan for any kind of 3G connectivity.