Today the porting guide for other devices is out : https://wiki.ubuntu.com/Touch/Porting
And it bring great news for anyone that is looking to run Ubuntu Touch on their device as it is based around Cyanogen Mod 10.1 .
Any devices supported by CM 10.1 should be able to run UT with relative ease.
I went over the guide and they used the Galaxy Tab 2 as an example of such a port.
From what I can see it is Android without the Java bits , Ubuntu itself runs on-top of the Android framework within a container. It's similar to how we ran till now Linux disto's on-top of Android but instead off using VNC to get access to an emulated X server Ubuntu uses Surface Flinger as it's display server.