The forthcoming Droid 2 and X Android devices on Verizon will be the first Motorola Android devices sold in the US from the manufacturer sold with digitally signed bootloaders in order to prevent flashing to customized builds of Android developed by the modification community.
While the locked bootloader does not completely prevent ROM flashing, it does make the process more complicated and involved than simply developing the ROM and installing on the device, as the bootloader has to be reverse engineered in order to allow flashing on the device, similar to the methodology for jailbreaking the iPhone.
