Microsoft does great work in researching static code analysis, I only remember their auto-complete ten years ago for C++ code and it was miles ahead of anything else. It pops up in just the right moment and it just feels like a genuine "code assistant" instead of just an auto-complete. Unfortunately I don't really trust MS with developing great OSX software (see MS Office for Mac) so I'm not sure I'd want Visual Studio. But if they could pull of a proper port, it would be awesome.