Issue #817 was closed with this response:

We fell a little behind. The Python bindings are done in SWIG. I think that can be quickly repurposed into .Net bindings, once done. So it shouldn't be too far out.

That was September 6th. It's now late October and there's been neither an announcement regarding .NET, nor an update to the original issue.

I'm eager to finally work with deep learning on Windows with C# instead of on Linux with Python. I'm sure Python bindings were helpful to some devs, but frankly every other deep learning framework already supports Python and C++. I'm surprised .NET hasn't been a higher priority, since it's something no other system has been able to provide. Now's the chance to become the de facto deep learning library for OOP development!