Well since HD-DVD announced that they had a new 51 GB standard (just be be sure to have more than BD), BD decided to respond. While it is uncertain if the HDDVD 51GB is compatible with first generation platters or not (hopefully it is since I do not want to have to buy a new one), it seems that the BD camp thinks their 100GB can be updated with a firmware patch.
TG Daily - Hitachi unveils 100 GB Blu-ray disc
PC Pro: News: Hitachi showcases 100GB Blu-Ray disc
Interesting working on 200GB, but not there yet...
TG Daily - Hitachi unveils 100 GB Blu-ray disc
PC Pro: News: Hitachi showcases 100GB Blu-Ray disc
Interesting working on 200GB, but not there yet...