At this year's Consumer Electronics Show, Toshiba announced that they were developing a triple layer HD DVD disc with a capacity of 51GB. This increased capacity gave a lot of hope to HD DVD fans as it would eliminate the primary advantage held by Blu-ray. Toshiba submitted their 51GB to the DVD Forum in April and according to a report by Screen Digiest, it was approved for production on August 31st.
The approval of Toshiba's 51 GB disc is good news for the HD DVD camp, allowing it to compete directly with rival Blu-ray Disc's (BD) dual-layer 50 GB disc. As with the BD50, it is likely to take some time for production yields to reach a commercially viable level. However, once this has been achieved it will arguably eliminate one of the principle reasons behind some studios' support of Blu-ray over HD DVD, thus potentially making it easier for Disney or Fox to adopt a format-agnostic position without losing face.
Surprising, the HD DVD Promotions Group has not issued any press releases regarding this. Until they or the DVD Forum confirm this report, I would consider it to be a rumor. If you'd like to read more, the entire report can be found here.