The image for RPiBuntu 15.10.2 is now available here that also contains support for the Raspberry Pi 3.
Besides support for the RPi3, this version includes Kodi 16 Jarvis and a further improved U-Boot package with a few new settings. In order to properly use the new U-Boot version, please add the following line to your /boot/config.txt:
See the our U-Boot documentation for more information.
Please note, while this image includes support for the builtin wifi of the RPi3, support for the builtin bluetooth device is still in development.
The MD5SUMS and the script to create own images can be found on GitHub. If you find bugs or have any problems, please open an issue on GitHub.