A workmate and I were talking in the hallway and he mentioned that he saw several newsgroup postings that implied that the lack of device custom control support in VS 7.1 was intentional. This couldn't be anything further from the truth!
Although we do support custom controls in VS 7.1, its quite difficult to accomplish. I've added a link to the left (“Custom Control Creation for Smart Devices in VS 7.1“ that guides you through the painful process.
The truth of the matter is that device custom controls are an extremely difficult problem. The problem is that a control may use P/Invokes which are platform-dependant and will not function correctly on the desktop. In fact the Compact Framework uses many P/Invoke calls internally (as does the desktop framework). But coming in MDC (mobility devcon), we will be showcasing some features that some people have already seen at PDC last year. Custom controls will be much easier than in 7.1. In fact, most of the time you won't even realize any difference between coding against the desktop framework versus the compact framework. And the foundation of why is based on retargetting. More on retargeting next time.