Verizon new iPad can run AT&T 3G
It seems that if you've bought a new iPad from Verizon, you can also run that device on AT&T's 3G network, and this was confirmed by a MacRumors member named jsnuff1. Of course, you'll need a micro-SIM for AT&T, but it looks like the new iPad can run on either Verizon's CDMA or on AT&T's HSPA+. You won't be able to get LTE speeds though, this is only for 3G. Apparently, the switch is pretty easy as well, just requiring you put in an AT&T micro-SIM and apply the AT&T APN carrier settings.
We were hoping this would happen, since the new iPad on both Verizon and AT&T has a world-compatible GSM radio, but it was expected that the Verizon branded iPad would be locked onto the carrier's network. Luckily, that isn't the case, so users are no longer quite as locked onto Verizon (except if you happen to be on contract of course).