A while back we made a repository where we can share & discuss designs for the OVM. Because all this tech is so bleeding edge it felt like having a more free-form repo to discuss designs & plans was the way to go as opposed to a more formal process like for instance PLIPs.
You can take a look at the repo here: https://github.com/plasma-group/ovm
If you have any designs, specs or comments, issues & PRs are welcome!