Starting with the OTA-4 Update, Ubuntu Touch has switched to Ubuntu 15.04 Vivid Vervet as code-base.
Canonical is focusing on Unity 8, Mir and Snappy and aims to create the first mobile-desktop convergent operating system and a system for the Internet of Things (ioT).
An independent user has asked if Canonical would add a USB GPIO breakout board on the phone, to permit the users access sensors and other hardware components, but a Ubuntu developer recommended Raspberry Pi 2 running Ubuntu Snappy Core for such tasks.
If you ask me, it would be awesome to use your Ubuntu Phone as a Raspberry Pi, because it is already equipped with a lot of sensors integrated in the phone case. The USB GPIO breakout board would facilitate users benefit from the screen, connectivity, sensors and other hardware pieces from the phone.