HTC has just announced the HTC First.
We don't know how many gigahertz it has (well, we probably do - just not officially), or how many geebees it's packing (we do now, see below), but we do know this: it's all about Facebook. And Facebook Home. And AT&T LTE speeds.
The HTC First is powered by a Qualcomm Snapdragon 400 processor, features a 4.3" display, and runs Android 4.1 with Facebook's Home software pre-installed. HTC and AT&T are remaining pretty quiet on other specifications, which makes sense, as this phone is not being sold on the merits of the hardware, but rather the software it's bundled with.