I dunno. I've never been pleased with the performance of optical media. I'd think being in a data center, heating up and cooling down from usage and storage is going to have very bad effects on recordable optical discs (CDs, DVDs, Blurays). Not to mention, it's always a pretty well known fact, consumer recorded media (the ones with dyes and stuff) aren't terribly reliable in the long term. My personal experience with recordable optical media is poor at best, I have very very few discs that've remained readable and error free after just five years of relatively decent care and storage. And this is not even using them every day, heating them up and cooling them down, just stored in a dark cool place.
Seems... overhyped. I simply can't come to believe this is an actual viable storage medium for any kind of large scale operation. But enh, if it works for them, good deal. Seems like you'd get more bang for your buck using high capacity tapes which hold up much better to heating up and cooling down.
The power saving claim also seems silly. This could be easy done with standard hard drives in a cartridge type system they're saying they're using, powering down unused drives and putting them into a storage position (though for me, I think it'd be much smarter to make the connector the moving part and just plug into the right bank of HDs, instead of moving HDs around in a cartridge.)
The more I think about this operation, the less intelligent and efficient it seems to be.