Well, the new SDXC standard has a theoretical limit of 2TB (preexisting cards are merely 64GB in size right now).
Flash cards are nice for keeping saved files, patches and DLC on the same cart of the original games instead of somewhere else. However, I cannot imagine flash cards to be anywhere as cheap as optical media They are optimal for handhelds but for consoles, they are way too small, IMHO. Maybe UDMA CF cards should be used instead when/if they get cheap :)
No foreign sky protected me,
No stranger's wing shielded my face.
I stand as witness to the common lot,
survivor of that time, that place.
- From 'Requiem' by Anna Akhmatova







