Mitsubishi Chemical has announced that they've started producing their new 8x DVD-R DL media. These discs are expected to hit the Japanese market by the end April. Here's part of their press release, translated from Japanese using Babelfish:

Mitsubishi chemical media corporation (head office: The Tokyo Minato-ku, president: Otsuka heavily virtue), this time, in the world for the first time 8 time fast entry corresponding single sided 2 layer DVD - the R for DL disk, we start sale from the April last third.

As for the disk which this time is sold, 8 time speed which until recently is speed of approximately 2 times that of the item * data entry of 1 becomes possible. In addition, continuing also the data of large capacity in 1 disk by using the record type DVD drive which corresponds to this product, it can write, the disk after the writing in conforms to the standard which overtakes playback compatibility at the time of the existing playback private DVD player and DVD driving of the personal computer.
Mitsubishi has not announced pricing yet but as you can imagine, these discs won't be cheap. If you'd like to read more, their entire press release can be found here.