The AT&T and Verizon versions are bootloader locked by default. An exploit has been found for the AT&T version, but the developer won't release it in case it can work on the Verizon version as well. Until the Verizon version is released everyone is in a holding pattern.
Sidenote: It is obvious Verizon gave AT&T this idea, so if you don't mind I am going to hate your cell phone provider with a deep passion for the rest of my life for working to ruin Android.
I don't blame you
but the 4G coverage area in the NYC metro region outweighs any hate I may have for Verizon (at least as long as my bill is paid for by work... if I ever get a new job and had to pay my own bill, I'd probably switch back to Sprint)