Recently AT&T demonstrated a video about testing of Android smartphones in its labs.

The HTC Liberty looks like the HTC Aria (its snapshot went online in late May). Because of this obvious resemblance, it was concluded that it is the same device. However, this is just an assumption, so there is a chance that these are two different smartphones anyway.
We are familiar with only a few of the HTC Liberty specs. Earlier this year, the HTC Liberty shone among seven new smartphones from HTC. The leaked documentation of the device says it has no physical keyboard and is equipped with a screen with a resolution of 320×480 pixels, though some experts insist on the presence of a sliding QWERTY-keyboard. Judging by the video, I can say it is equipped with the HTC Sense UI.
I guess this new smartphone will be announced this summer.