Source from Pioneer Official News
A Japanes compnay called Pioneer is developing a disc that can stores 400GB of stuff. Pioneer said their disc will be similar to the blue ray disc which has double layers and holds 50GB, but Pioneer will further the disc layers to 16 layers. Pioneer released a sample today (Asian time 7/8/2008) a single disc that can stores 400GB. Moreover, Pioneer said there is possible chance that their new disc will be compatible with the nowadays blue ray disc readers because their new disc’s ideas are base on the blue ray technology.