Disk drive space is, for many purposes, effectively a solved problem. Disk drive speed is another story. Moore's law projections suggest that this is likely to become much more true in the future. See this interview with Jim Gray for more perspective. Hard disks won't necessarily die, but people will have to learn to think about them differently.

Incidentally 120 Mbps is not that fast. A Mbps is one megabit per second. 120 Mbps will transfer 15 megabytes per second. If you really had a 2 terabyte card that you could access at that speed, it would take a day and a half to scan it. By contrast people are now wiring up gigabit ethernet which transfers data between computers about 10 times as fast.

Of course 2 terabytes is the capacity of the format, not the current cards. The format is meant to anticipate what might be possible someday. Actual cards are not going to get there for a long time.