To be honest, as long as VS Code is free-as-in-beer, has a plugin-in system that's flexible enough for the community to go nuts with, and can adequately serve as the primary development environment for an ASP.NET app... then I'm delighted.
However, perceptions mean a lot, and in the long-run I just don't see it getting uptake from the Python/Ruby/Node.js crowd without being open source. More of a marketing issue than anything else (although there's also the concern that MS could abandon it someday).
I believe that debugging support on VS Code is currently limited to Node and Mono (and that's only on OS X/Linux) [2]. The team(s) behind OmniSharp (that is the various editor plugins) do desire bringing debugging support to one or more editors.
[1] http://www.omnisharp.net/#integrations [2] https://code.visualstudio.com/Docs/debugging#_common-questio...
VS Code utilises[1] OmniSharp-Roslyn[2] (which is an open source project not started by MS) to provide intellisense and refactoring for C#.
If you want to use something that is fully open-sourced (since day 1) and also utilises OmniSharp Roslyn, then check out OmniSharp Atom [3], which is an Atom plugin written mostly in TypeScript. OmniSharp Atom and OmniSharp Roslyn are both very welcoming of contributions. So if there's something that you see that's missing, feel free to send a PR :)
[1] https://code.visualstudio.com/Docs/languages#_c35
[2] https://github.com/OmniSharp/omnisharp-roslyn
[3] https://atom.io/packages/omnisharp-atom