Yes the development model we're focused on is one where you build a Universal Windows Application and then deploy this to your Raspberry Pi 2 (which can run in headless or headed mode). At this point we're focusing on enabling the development of IoT style devices which tend to be fixed/limited function (ie the application is also the "shell"). These same applications will work on your PC (or phone) so you can actually do your testing and debugging on whichever device that you prefer.
While our development experience is optimized for a Windows 10 PC (and the preview release requires Windows 10 PC for programming the image as well) there is no runtime dependency on a Windows 10 PC.
I encourage you to check out some of the projects we've posted at www.windowsondevices.com
to start getting a feel for the capabilities of the system. This is a very early release, so please provide us feedback and we'll incorporate it in our regular updates.
Pranish Kumar (firstname.lastname@example.org