@ James C4S,
I dont believe the answer is that simple, No to the normal everyday Arduino tinkerer, it's more trouble than it's worth, especially given the amount of "my 1604 lcd wont work" post's on this forum
High capacity SD cards do make HDD's somewhat redundant, but there is coompact flash if people do want large fast storage, they can be used in 8bit mode as i have done myself with microchip pic's.