Same deal...we would love to add it but none of us use Clojure. Anyone who's interested in helping us add it (on a contract basis) should email me at sqs at sourcegraph.com. Or follow the issue at https://github.com/sourcegraph/sourcegraph.com/issues/154.
I'd love to see C# support. I suspect you could achieve this via Rosyln [0], but I don't think I'd be able to accomplish this myself. I'd be happy to chat about it, though.
[0]: http://msdn.microsoft.com/en-us/vstudio/roslyn.aspx