Who knows? Society has gotten it in their heads that cartridges are prohibitively expensive, but new technologies are constantly emerging.
I, for one, would love to see an MRAM based system. Super fast, super reliable, and quite possibly, super small (physically, that is). Obviously, it'll be a while before the 4.7GB capacity is feasible in a managable size (I'm think the size of compact flash card) , but when it is...dayum