A new form of high-definition HD DVD disc has recently been approved by the DVD Forum which is based on a triple-layer design, this allowing for up to 51GB of data storage. Further advancement in the layer structure allows each layer to hold up to 17GB as opposed to the previous 15GB limitation, thus the three layers making up the full 51GB capacity.
Further to this, the new format has already gained a solid backing by the Disney giant (who happen to be one of the strongest backers of the Blu-ray disc format). You can read about that here.
It is not yet clear as to whether or not this new type of disc will be backwards compatible with existing HD DVD hardware.
XBit Labs have the full story.
DVD Forum, the international organization that oversees standardization of DVD and HD DVD optical disc formats, has finally approved version 2.0 of triple-layer HD DVD discs. The availability of physical specification of an HD DVD read-only media that can hold up to 51GB of data will allow the manufacturers to start producing the appropriate disks, whereas content producers may now start to think about how to use additional capacity.