We are making headway. Our current plan is to not have any sort of official plug-in SDK for the initial release of Mac Rhino. This is only unofficial because we don’t want to tie any of our SDK to this initial release (or make promises we can’t keep) and we don’t have the tools/training built up around .NET development on Mac that I feel we should have in place in order to provide a professional development setup.
That being said, we are successfully compiling and running our python plug-in for Mac Rhino. We are also in the early stages of investigating the use of a cross platform user interface toolkit that could be used for writing nice looking UI on both platforms. I also have a debugger working for Xamarin Studio (.NET IDE for Mac) which I can use to debug .NET plug-ins.
We will start rolling out announcements for ‘early adopters’ to start playing on Mac Rhino development once we are a little more comfortable with our user interface decisions.