I think I'll wait until I can fit all of my music uncompressed onto one great big solid state drive.
Hard drives with moving parts fail so I won't be going that way.
Currently the best solid state drives have mtbf's in the same general range as enterprise class regular disk drives ie. ~ 1,500,000 hours or over 600 years. Of course some drives of either type will only last 15 minutes or more likely just untill you get everything loaded on them. They will both fail, do you feel lucky?
However, currently there is no comparable capacity match, so using an enterprise class disk drive is still by far the best bet for a large quantity (1 terabyte +) of data purely based on mtbf figures 1 drive against multiple, smaller, solid state drives.
Also be sceptical still of the write cycle limits of flash drives, unfortunately they are so new (both large chips as well as drives) we don't have a lot of real data points to use only projections based on very short real periods of testing. Normally we need at least a year of real data to be truely accurate on the calculations especially with time estimates this high.
Your best best is still anything in an enhanced raid 5 configuration (hot spre). MTBF is estimated at over 45,000 years with regular old disk drives. Solid state drives have their place, but they are not a cure all.
I know .... too much information, I couldn't resist though.
Brian