They will sell enough as signs and novelty pieces in corporate offices etc. however they don't really have much use. It's a bit like 3D TV, cute but distracting.
I have used a projected screen as part of trading setup for years, I can focus through news, long timeframe charts and other stuff displayed on a glass sheet. The normal monitor screens are behind, otherwise its basically my angled desk. It is very niche, I still go to a real TV or my wall projector for movies.