HTC is getting set to release the HTC One Developer Edition which will come with an unlocked bootloader and be SIM unlocked. The handset will be released in limited quantities alongside the subsidized version in the U.S. and will cost $650. You will get the same specifications as the subsidized HTC One including the 4.7 inch touch display with an FHD resolution, up to 64GB of internal storage, a 4 megapixel camera with UltraPixel technology which is capable of 1080p HD video capture, a secondary camera for video calls and a 1.7GHz quad-core processor with 2GB of RAM.However keep in mind that this device wont support the T-Mobile 3G bands and you wont be able to enjoy fast internet on the network unless you are in an area which supports LTE. Personally we are not fans of carrier locked handsets, especially in cases where users are still tied to a network after paying the full cost of the device.
Given that the users in the United States have the luxury of purchasing subsidized handsets, its not fair for manufacturer's to push them into purchasing handsets at full cost. After all we deserve full access to the device we pay for – subsidized or unsubsidized.
source – HTC Blog | Engadget