However, Motorola is saying that the warranty could still be considered in place if the bootloader is unlocked and the damage is an unrelated physical malfunction, such as a “bad volume rocker,” or a “failed speaker.” As long as there is no sign of physical abuse on the phone, honoring the warranty on such unrelated physical issues will be considered. According to the forum manager, “The key is that the problem can’t be traced to software or abuse.”
The same rules will apply to the MotoCare extended warranty. So if you are a modder, you still might be able to have coverage on some issues. This apparently will be decided on a case-by-case basis at Motorola’s discretion.
source: Motorola via AndroidandMe