HVD is the way to go. BluRay is so 2009.
http://en.wikipedia.org/wiki/Holographic_Versatile_Disc
6TB storage on a disc. GG NO RE.
:D
Seriously: I can see them using BluRay, but it won't be a big deal. A BluRay will be near the 50 Cent mark for production and it already uses MS software. I doubt they will be paying much and Sony will get even less. Of course fanboys will make this look like an awesome cash-cow for sony, but it is not.
Imagine not having GamePass on your console...