I have this same problem.
I have multiple windows in the autohide state and I'm getting really frustrated with not being able to see them at design time.
An invisible at design time XAML construct is damn hard to edit in a GUI visual editor.... :-(
Is there some way to make auto hide windows and their content visible in either VS (I use 2012) or Blend?
If not, what is the recommended design work flow?
I've been doing property grids in an MDI window then copying the XAML to the auto hide window - which is "a less than satisfacory" work flow approach.
I've thought about making the windows as normal open MDI windows (so they are visible at design time) and then changing them to autohidden programtically when the app starts. I'm not sure yet how to do that (and don't really think it should be necessary).
How do others design invisiable autohide windows?