Folks - we're just updating our main data projector, and the new unit will be widescreen. But to save funds, would it be possible to run the onstage monitors, driven by the stage display output, as regular 4:3 displays, or does the stage display have to have the same output resolution as the main display? If it is possible, how is the output re-scaled for the different shape?

If you are using a video card that supports at least three different extended desktops or three independent outputs, you can do this.
If you are using the matrox dualhead2go, you cannot use a different resolution for foldback and front of house.

Two video cards, so four full outputs. So how does EW configure the stage displays if they are 4:3 as compared to a 16:9 main output? Does it just letterbox everything, or does it re-format song text?