Today, Samsung has announced that they will begin to sell an off-contract ‘developer friendly’ Galaxy S III via their online store. This phone will only work with the Verizon network. Samsung is doing this because the standard version of the Verizon Galaxy S III has a locked bootloader, making it hard to install different ROMs, etc. The reason that Samsung isn’t releasing a developer edition Galaxy S III on other carriers is because they have decided to keep their bootloaders unlocked.
The developer edition Galaxy S III will run you $599, the same price as an off-contract standard Galaxy S III from Verizon. Keep in mind that Samsung will not cover this phone under warranty if you screw up when flashing the firmware.