I run Windows but not Visual Studio. I'm using bootcamp. It works fine.
When you're first running the installer, the dialogs/interface elements are tiny because of the retina resolution. However, once the full operating system boots up, text and interface automatically scale and look great. That's assuming you're running at the native display resolution. If you play games or whatever at non-native res, you do get some fuzziness from interpolation. Also, some applications appear to have issues with high-resolution and look pixelated.
Also, I've only been using Windows on my 15" retina macbook for a little while. There may very well be issues I haven't run into yet that could come up in the future.