Good news. I've ported the piCore on the new Orange Pi Zero. Non with the 3.4.113 kernel.
The board works well, the idle consumption is 100mA@240MHz, the peak full speed consumption is 240mA@1,2GHz.
Compared with RPi3, the boot time is twice, but than the speed is comparable.
The on board wifi is working too, but not as good as the external Realtek based one. Seems that there are still some issues with the wifi driver and need tweak.