Summary
Visual Studio .NET has greatly simplified the process of creating custom controls. Because this is the case, the soon-to-be billion-dollar control market will increase even more due to the increased number of controls that will likely result. The question you still have to ask yourself, however, is what language to use for your creating controls. As of this writing, Visual C++ .NET does not have a Windows Form Designer. Based on this fact, do you immediately rule out Visual C++ .NET in favor of one of the other .NET languages? As I've said before, you have to weigh the advantages and disadvantages of each language and decide for yourself based on your project objectives.
This hour you learned how to create a custom control using Visual C++ .NET. Although you didn't know it at the time, you created a managed C++ application in order to facilitate easier testing without having to close Visual Studio .NET and reopen it each time to build your control, as you have to do with a Visual C# test harness. You learned how to create a custom property for your control and also how to change the behavior of that property, as it's shown in the Property Browser. Now that you have the basics of control creation down, you're on your way to tapping into the control market with your own custom controls.