The 50GB storage capacity of the Blu-ray format is under threat according to this editorial at gameplayer which speculates that Microsoft and Samsung could partner up with technology that allows up to 12TB of storage on one physical disc.
"DVD in its current format will not cut it in the next-generation of gaming. With top-end games already seeping over the edges of DVDs paltry 8GB of storage space, it's a sure-bet that games are simply going to need more space going forward. PlayStation has Blu-ray, but Microsoft has nothing."