The Japanese website, AV Watch, has posted some pictures from the 8th annual Data Storage EXPO. On display were prototypes of TDK's 6x BD-R and 100GB BD-R media. Here's part of their report, translated from Japanese:

With the TDK booth of data storage EXPO, besides the fact that last year the exhibition of the BD-R disk of similar 4 layers /100GB was done as a technical exhibition of the BD-R disk, the sample of the BD-R disk which corresponds to 6 time fast record was displayed.

But with Blu-ray Disc Association, the stage which standardization has not ended concerning BD-R of 4 time fast record "standard deciding, if the device appears and only does, when it can put out the product even directly. But timewise circumstance of decision, we would like to sell 4 time fast BD-R disk within 2006", that we have done, the possibility standard of 4 time fast disk deciding within year was suggested.
If you'd like to read more, AV Watch's entire report can be found here.