Today, the CEO of HTC, Peter Chou, has made an announcement on the company's official Facebook page about HTC "reviewing" their bootloader policy:
There has been overwhelmingly customer feedback that people want access to open bootloaders on HTC phones. I want you to know that we've listened. Today, I'm confirming we will no longer be locking the bootloaders on our devices. Thanks for your passion, support and patience.
Having an unlocked bootloader means that owners of their devices have complete control over them. This can be quite crucial for when the device reaches the end of its support lifecycle and is no longer receiving updates from the manufacturer, as hobbyists and enthusiasts can take the latest Android source code and port it over themselves, or create optimised "roms" that increase battery life among other things.
There's still no word on how this move will affect existing devices that have already been locked down, or if HTC's latest device, the HTC Sensation, will receive an update to unlock it in the future.