So developing with the Rift as a primary display is a huge pain. It appears that even the runtime/SDK demo's require the rift to be configured as the primary display in order to work properly (on OS X at least, I haven't tried in Windows recently). Launching apps from a traditional desktop (not VR friendly) is cumbersome and annoying.
I haven't yet attempted to get my own native app to attach the window/rendering view to the Rift with SDK v0.4 while configured as a secondary monitor. Is this even possible, especially considering that OS X doesn't support Direct HMD Access mode?