Update: The JetBrains are working on Resharper for C++.
While not quite as good for C++ as Resharper is for C#, Whole Tomato makes a product called Visual Assist X which handles C++ and does it in a reasonably performant manner.
Developer Express also makes CodeRush, which provides more features than Visual Assist, but which is also a much harder drain on your computer, and also which occasionally makes mistakes -- most constructs using macros won't work correctly with CodeRush. Note that as of 2013-05-31, CodeRush has deprecated their C++ support.
Resharper and Visual Assist are nice to have around -- I occasionally flip on CodeRush for some of it's better refactorings, but most of the time leave it off because Visual Assist X's code completion assistance is better.
Do keep in mind that installing any such plugin requires running the IDE in Integrated Mode (rather than Isolated Mode). This means:
- In Visual Studio 2012 or earlier you'll need a full version of Visual Studio, not one of the express editions. If you're a university student you can probably download a full copy from MSDNAA. If you're a non-university student or your university doesn't provide MSDNAA you can still download a full version from DreamSpark.
- In Visual Studio 2013 or later you can use the "Community Edition", such as Visual Studio Community 2013.