Personally I like the idea of designing a version of the MiniMig to follow the mini-itx standard layout. It would open up the possibility of average people being able to use standard cases and still allow case modders to fit the MiniMig just about anywhere they want it to go.
As for the whole IDE vs SATA thing I don't think IDE is in any danger of "disappearing" any time soon so if it could be added in future versions I don't see why someone shouldn't do it.
Now granted that's just my biased opinion but I say if you can convince your friend to take on the challenge then go for it :-)