A major problem in that environment will be the glare from the windows on a highly reflective or shiny screen surface. Think about one of the new DLP's or LCD's with the matt type screen surface. They are much better at rejecting that kind of glare. With that said. This question of ambient light is something we have to deal with on an ongoing basis when designing a system, or selling a display or projector. As is the case with a room with poor acoustics. The best speaker in the world won't fix it, nor will the best display solve the ambient light problem. The answer is to find solutions that deal with the environment you are working within. And make sure the client fully understands the parameters well in advance. A few dollars spent on window treatment goes a long way