I've been playing with Windows 10 on Raspberry Pi for a while. It works really well. It is now my weapon of choice for proper embedded applications.
The Arduino is lovely for tiny apps, but if you find yourself adding SD card interfaces and network adapters and displays you might as well move up to the Pi and get the benefit of C#, Visual Studio and a properating system like Windows 10.
Up until now I've been tied to a network cable as the previous versions of the Windows 10 Raspberry Pi platform didn't support WiFi. But the latest one does. You have to use the "official" Raspberry Pi WiFi interface, but as this is one of the cheapest (at six pounds) I don't see this as a problem.
I've added one to my Pi and it works fine. The only problem I've found is that at the moment it doesn't support WiFi connections using the "organisation" authentication that we have at work on the campus network. However, it works fine at home my my domestic network. If you are writing Windows 10 applications for Raspberry Pi you should get one of these for each of your systems. They also raise the lovely prospect of properly powerful connected applications.