Traditionally they hold from 25-50GB on a single-layer, and 50-100GB on a dual-layer. Their size makes content such as God Of War III possible. But what if they were to get bigger?
Well, they are. New 128GB BDXL discs are ready to go, but only for commercial usage. They won't work in your current PS3 because, well, the PS3's laser can't read it.
Playstation 4 then?