Say, RAID-6? That's what you do for drive failures. The problem with drive failure isn't replacing the drive, but the data and the downtime.
With most workstations, this is easy, you can get a RAID controller, usually integrated on the board (Dell's PERC 710s are great) and you can knock in a bunch of drives and go. High performance, high resilience. No such luck on this new Pro.
Another option would be a good external system. Maybe a heavy hitting iSCSI or FC array. That's where you go for really high end, lots of storage, reliability, etc. Ahh well you are kinda screwed there too. No cards to add FC to the pro, and OS-X has no iSCSI initiator, which is shocking for a modern OS, Windows got it in 2003 and Linux in 2005.
Also you might want to look in to SSD failure rates. They aren't particularly high, but they aren't particularly low either. Oh, and they are workload dependent as well. I loves me some SSDs, but don't think they are rocks on which you can build your house.