Good point. The best answer there is: that's what Time Machine backups are for. Time Machine backups lag your actual storage by 10 minutes to an hour, but it's okay for most uses.

If you're worried about important data, you'd want to use external storage arrays to store your pictures/videos/genome data. Then your redundancy is handled in individual storage chassis configurations. Promise and LaCie have popular faster-than-a-single-ssd thunderbolt arrays.