Consequently there have been rumors regarding Microsoft installing a new type of a keyboard for Windows Phone 8, which will be well fitted especially for single handed thumb usage. Accordingly to the reports, screenshots of the keyboard, known as the Arc Soft Keyboard are doing the rounds of web.
The front face of keyboard seems to have been designed to conceive one-handed thumb typing without having to look. The layout groups many keys together, avoiding grammatical interpretation to decide what word is being typed.
This keyboard could perhaps also come in the Windows Phone 7.8 update for the current crop of Windows Phone devices.