HTC M4 could be HTC First minus Facebook Home
It doesn't make much sense to make phone only for one carrier, now, does it? In the spirit of HTC Droid DNA/HTC Butterfly phones, HTC might be releasing its First handset that some dub the Facebook phone, in an M4 variant without the Facebook Home integration and other social networking goodies.
Thus the rumored specs are a 1.2 GHz Dual-Core Snapdragon 400, 4.3" 720p display, 1 GB of RAM, 16 GB of storage, and an HTC UltraPixel cam with unknown resolution, plus a 1.6 MP front-facing shooter.
HTC M4 has leaked before, and the HTC One was codenamed M7, so we certainly won't be surprised to see something lower down the smartphone chain from the Taiwanese soon.