The new iPad( iPad 3 or iPad 4G) is sold officially unlocked. It means if you have bought for Verizon, it will also work for AT&T, and you dont need to do any thing except just changing SIM and put internet Setting(APN to be exact). Check the details how and what we find out this.
Some commenter named “jsnuff1” first make a note at MacRumors Forum thats you can use AT&T MicroSIM even if you bought Verizon version of The new iPad. It was surprising as we also broke the news that this iPad will have separate hardware for Verizon & AT&T, as mentioned by Apple Website.
The user also made a video, check it out
After that news spread out, people started making different kind of test. So after all it seems all it needs to use a different SIM is just adjust the internet settings, means just update APN setting accordingly.
But as AT&T has different approach over LTE 4G network, so it will be some kind of 3.5G, just like some European network. So speed over AT&T Data network will be that good, not upto the 4G mark. But Mashable mentioned “AT&T data cards will only be able to connect to the carrier’s 3G, HSPA+, and EDGE networks rather than the much faster LTE network the AT&T iPad runs on”. But it also means you will be able to use it worldwide with any 3G, HSPA+, and EDGE networks.
Its Officially Unlocked:
Yes, it means that after all The new iPad thats been shipped on the first day with iOS 5.1 is actually Unlocked. so you could use any SIM, to be exact MicroSIM,(But you could convert normal SIM to MicroSIM, follow this guide of ours). So when you will be traveling within your country where your network is poor or even traveling any where in this world, you could use your new iPad 4G with any network and will get 3G, HSPA+, and EDGE networks data speed. There is speculation that Apple might block that hole with an iOS update. We are not sure if it will happen soon or even ever happen, but to be safe dont upgrade to any new version other then the initial one you got while you bought The new iPad, if you care about unlock and need to use different network then it originally comes with.