In our operation, we have found it somewhat important to consider the purpose of the storage and pick the appropriate media depending on that purpose. As a recording and video production facility, we have terrabytes of data which we have to move in and out of operation. We use an online, nearline, and offline thought process. The online stuff is of course on the local server. In our case I use NearLine to refer to storage used for quick restores in the case of a server failure. This is usually sets of terrabyte external hard drives stored both onsite and offsite. They can be plugged in quickly in order to rebuild a file server.
Where it gets interesting is offline storage. In our case this may be a video project which we know we may need to come back to in a year, but does not need to be immediately online. We need an archival media for large amounts of data. This is becoming more and more important in my industry as many of the hi-definition cameras are shooting directly to banks of 16 or 32 GB P2 cards so there is no tape or film media to go back to. The initial product is digital files. I know many production companies that are using firewire drives for this offline storage purpose. They copy the project to an external firewire drive and set it on a shelf.
However, we have had an abysmal failure rate on these drives. We had close to 20 of these drives at one point and have sent over a third of them back for repair at one point or another. After losing both our primary and secondary external drive backup for a project in the same week, we finally abandoned that concept and have returned to tape for long term storage. In our case LTO4.
To summarize, IMHO the media to use depends on the application and the longevity. We have tapes from over a decade ago that restore just fine. I am not convinced that a hard drive sitting on a shelf for ten years will neccessarily come back though.
