Hi Roman,
a good starting point is to setup the XobotOS development environment on a dedicated machine or most commonly as a virtual machine. Then try to run the samples. The guide in our wiki gets the basics done, but at least for me the samples did not work completeley as intended, which means that there are a lot more hidden issues in the code than meets the eye.
The current project stage is about getting the original XobotOS and its samples fully working and running on Ubuntu 14.04 i386 in a reproducable way so we get an understaning of how the Xamarin team did the conversion. In the next step we'll expand it to not only convert part of the system, but the whole Android 4.0 part that depends on Dalvik.
In order to work on the project full time I am currently working on a Kickstarter campaign to raise the necessary funds. If all goes well we might be able to put a small team to work on this.
Any new insights you can bring to the table are highly appreciated!
Cheers,
Bastian