I have a rather large number of irreplaceable files burned onto three Blu-ray discs, which are now sitting in my safe deposit box. There is a need, just not a big need. And I do trust optical discs more than hard drives. I've never had an OD failure, but I've had 4 or 5 HD failures.
Ok... For that I would want a blueray disk
If you will be making regular backups, then I still stand by the fact that magnetic storage is a better solution. In 15 years I've only had 1 harddrive fail on me. Backing up to a RAID storage system also provides protection against such failures. For less than 250USD you could build a 1TB RAID NAS. (Built from two mirrored 1TB drives storing redundant data). This would be fast and easy to store information to regularly and provide a good protective system for data. Most companies don't resort to BD backups and go with RAID systems if that's any solace to you about reliability.