Certainly this is a trend that is a long time coming, but the recent increase in the MPG targets are a de facto requirement for polycarbonate glazings. As much as PC will reduce car weight, it will also free up design. Look at the Qarmac concept car:
Those C-shaped windows just can't be done in glass. How much innovative design is being stifled because the glazings are still glass? Outside of the weight considerations, how much does that hurt aerodynamics?
Naturally, Bayer and SABIC, the two biggest manufacturers of PC are in the game, but in slightly different ways, although both are operating subsidiaries (BMS and Exatec respectively) which provide the materials. PC can't be used straight as it doesn't have the scratch resistance or weatherability (it will oxidize and turn yellow courtesy of the photo-Fries rearrangement) without a coating. BMS is going with a wet coat while Exatec is going with a plasma coating.
Sun/moon roofs are already being made so obviously the UV protection is solved to some degree. Given the repeated rubbings and abuse that windshields take, I would expect that application to be the last to go, but the sidelights should provide lots of fun in the meantime.