Courtesy of Nick Hodapp, here's a great example of using Managed C++ to quickly and easily make existing C++ functionality available to .NET apps.

It's a short and sweet sample, but I like it because it shows

1. how easy it is to write a .NET class that wraps existing C++ functionality
2. the relative ease of fooling the existing C++ code into calling .NET code for drawing

Obviously the scale of effort for this tiny project is considerably less than what it takes to convert a major existing codebase to Managed C++, but it's excellent for a quick overview.