"... although I am surprised that it is not designed to support anything other than Python ..."
Why? The Google "big 3 language" choices are Cpp, Java & python ~ http://panela.blog-city.com/python_at_google_greg_stein__sdf... You may see perl or other languages but the "big 3" are the officially supported ones.
"... python ... but it will be a non-starter for many developers. ..."
I find that an interesting statement. Why say that? Python is a pretty easy language to learn & use.