Interesting that they decided to release 1.0 before sorting out the coreclr/dotnet story. My understanding is that Mono is still the best way to write C# with VSCode, even on Windows.
Here's a blog post with bit more info on setting up VS Code with the pre-release version of the C# extension (and debugging support): http://www.tattoocoder.com/setting-up-asp-net-core-debugging...