Blue Laser Leapfrog
Not only that, the new disc is capable of recording data at twice the rate originally specified for BD (72 megabits per second compared with 36Mbps). According to Nobuyuki Koike, a spokesman for TDK, the faster write speed is achieved by using a more powerful laser as well as making some changes in the recording-layer material. The Blu-ray Disc Association (BDA) has already standardized a 2X version of BD-R (write-once) and BD-RE (rewritable) discs.
Sony spokesman Taro Takamine says that the current road map calls for 4-layer BDs to enter the market in 2007. Of course, this road map could change at any time in response to new technological advances or compromises that might or might not be reached with the HD DVD camp. And as far as I can tell at this point, no one is waving a white flag.