I've been wondering about this for a long time. Seems to me that projection is limited by the contrast ratio, since the black areas never seem black enough in relation to the bright areas. But, if the bright areas suddenly got amazingly brighter, then we'd be onto something.. Lasers could do just that.
Laser TVs launching Christmas 2007 - Engadget
The new sets are touted to be half the price, twice as good, and use a quarter of the electricity of conventional plasma and LCD TVs and be half the weight and depth of modern plasmas.