Maxell has announced that they will be releasing their new inkjet printable 4x BD-R media to the Japanese market on November 26th. The company also plans to ship their double layer 50GB BD-RE media at this time. Here's part of their press release, translated from Japanese:

This time Maxell will release a recordable BD-R discs, 4x speed record corresponds to a disk to move to significantly reduce the time. Additional label, the ink jet printer compatible with the printing layer and label printer that can print directly, as well as water-based ink pens HAJIKAZU also can be hand-painted. In particular, the "super-whitening HIROBIRO label," The adoption of BD-R discs, the disk around the parts of the color Merat, wide can be printed, recorded, as well as from the original library building have fun MASU.

The simultaneous release of the corresponding single-sided double layer recording rewritable BD-RE DL disc (50 GB), as is the quality of high-definition video in 260 minutes that long recording, and the VHS videotape sensation, KURISHI recording can be.
While Maxell has not announced any prices, AV Watch expects their inkjet printable 4x BD-R discs to cost about 1,700-1,800 Yen ($15.50-$16.40US) and their 50GB BD-R media to cost about 5,500 Yen ($50US). More information can be found here.