The HTC One may be changing sizes in smaller(4.3") and more phablet 5.9" sizes in the future.
According to some sources HTC is working on a phablet with a 5.9" 1080p touchscreen and a 2.3GHz Qualcomm Snapdragon 800 processor. The phablet with the codename T6, which may have 2GB of RAM, 16GB of storage and microSD card slot.
There are other reports of an HTC One mini, a smaller version of the HTC One in black shown in Estonia. Reportedly called the M4 the HTC One mini is expected to have 2GB RAM 16GB of internal storage and 4MP ultra pixel camera with a release in August.
The HTC One mini may have a 4.3" 720p touchscreen which is still larger than the iPhone 5. It appears HTC is following in the shoe-sizes of the Samsung Galaxy S 4 which come in a mini size and phabulous phablet the Samsung Galaxy Note II/III.
Reports suggest that production for the HTC One mini will begin in July and launch later.
The trend now is that there be one product name and then different sizes. We still can't figure out why the HTC One S and V launched before the the HTC One.