My Nvidia driver has a screen for setting up multiple displays. I'm guessing that your driver will not send your screen to the 'video out' unless told to do so and also given some device information.
BTW, last week was the first time I set foot in a home theatre store. We were in the shopping center for something else and I thought I would take a look since they also had a 'tent sale' outside.
A 'low end' option including low-end hi-def projector, screen, and theatre seats was about $6,000 or something like $200 a month.
I admit, going into the demo small room and seeing a high-def Dave Matthews concert on the projection screen was amazing, especially sitting in the leather theatre seats.
I ended up buying 5 slightly used tin poster reproductions from their tent sale for $15.
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