2GB cards is great for portables. But for 50GB to 100GB and up, I don't think it's possible within the next generation.
We had a big drop in price when flash controllers started to map bad blocks in factory (better yield, larger chips), and another big drop when we switched to MLC, but there's nothing else in sight as far as I know for cost reduction. It's a silicon chip, so the cost of production cannot really go down any faster than the wafer production cost.
How much die area is required per GB, or transistors per GB, and how much more is needed for better speed?
What's the cost per area at 20nm? At 14nm?
How small can they go in the future and will it cost less? When?
They are not selling you blanks. How much time is needed to copy and verify 100GB on a flash chip at the factory? Lead time to have enough supply for launch? Cost of that factory?
They are now having problems with the smaller flash cells at 25nm and 20nm, it's more leaky and is less reliable, it will probably get worse at 14nm and beyond. I don't see the price coming down enough in the next 5 years, let alone by 20x in 2 or 3 years for the big flagship games. They wouldn't even be able to release a direct port of the flagship games from PS3, let alone improved versions with higher res textures and models.
For a price reference, according to iSuppli it costs Apple 40$ for 32GB flash chips. Now please argue that Apple isn't in a position to negotiate the best prices. Prices of dumping overstock are not comparable to ordering millions of chips per month. Current prices for the high speed SD cards is also extremely high.
http://timenerdworld.files.wordpress.com/2011/10/isuppli-iphone-4s-bom.gif
EDIT: Latest Intel/Micron 8GB MLC at 20nm HKMG is a
118mm^2 chip, planned for late 2012 production, so you need
944mm^2 for a 64GB chip with that latest process. Price is expected to remain high due to demand.