Mitsubishi Chemical has announced that they will be releasing their new 8cm DVD-R DL media on the Japanese market in late August. Here's part of their press release, translated from Japanese:

Mitsubishi chemical media Ltd. (The headquarters: the Tokyo Minato Ward and president: Otsuka heavy morality) begins two one side layers DVD-R for DL (The write-once type: for one time recording) as 8cmDVD disk for the video camera, and it begins to appear in the world and sales will begin in the end of August this year. Moreover, it will begin to sell it at the same time by one one side layer 8cmDVD-R and as much as one one side layer 8cmDVD-RW widely widespread for the video camera.
This new media has a capacity of 2.6GB, giving video camera owners the ability to record 54 minutes of video in SP mode. Mitsubishi has not announced a price. However, the media is expected to run about 3000 Yen. If you'd like to read more, the entire press release can be found here.