Taken from here: http://www.watch.impress.co.jp/av/docs/ ... /ces10.htm
The DVD+RW alliance 5 days (local time), holds concert, Hans Driessen of Philips Research explaining the DVD+RW-RELATED road map. Decision of DVD+RW 8 time fast standard ended, made the schedule where the corresponding product is sold in April. In addition, concerning 12 time fast DVD+RW standardization and product throwing within year it is put out as goal.
Furthermore, with the media after 8 time fast DVD+RW, modification of modification of the pigment of record layer and adoption etc. of new ライトストラテジ because of that, 8 time fast DVD+RW disk to be done, not be able to record with former 2.4/4 time fast DVD+RW drive, only it reads and it becomes correspondence.
From what I can gather from the translation, 8x DVD+RW isn't fully backwards compatible with older drives either. It's readable in them.. but they can't write to it.