Back in the early days of Android, it was commonplace for handsets to have a call start/end key (like the T-Mobile G1, HTC Hero, and others). For the sake of keeping the hardware sleek and as minimal as possible, OEMs have since opted to leave out these two keys in almost every Android phone to come out in the last couple of years. But we must say: having the dedicated buttons was a big convenience. You could more easily end a call, and getting to the phone application was almost instant.
Based on this rendering we found, HTC might be going in the opposite dirrection. The handset pictures has certain characteristics of the midrange HTC Aria, but it adds the dedicated call start/end buttons around the optical D-Pad. Also noteworthy is the bold front-facing camera that is surrounded by a nice chrome ring. The earpiece is also quite different than what we saw on the Aria. The screen size is likely to be 3.2 inches or smaller, which would make this a petite device. Could this be the Aria 2? We'll have to wait until MWC to find out!