I have a microUSB - HDMI adapter bought off of ebay, and an international Quad core HTC ONE X.
I tried connecting the adapter (power and signal cables were both attached) but the orientation is fixed to portrait. If I set the autorotation on the mobile to on, and rotate the landscape, the input on the HDTV is rotated as well but the picture stays within the portrait viewing area. So, I have huge black bars all around the picture.
i'm running CyanogenMod, on the latest nightly.