Yes, the Blu-ray disc guide (and CD-R guide, and historical VHS/S-VHS media guides) will all be out by end of year.
A typical hard disk is expected to fail within 5-10 years, depending on use, environment, and (if applicable) storage conditions. Google did extensive credible research into this area, and I've attached the PDF. A
BBC article from the time did a quick overview, though I suggest reading the entire PDF in order to gain more than passing summarized knowledge on the subject.
The past decade has proven that journalists do a half-assed job when it comes to verifying media research claims. So any news outlet reporting a "million year drive" is simply passing on propaganda, as far as I'm concerned. Of course, even calling it a "hard drive" is misleading, because it's etching data into platinum and sapphire, not too dissimilar from a vinyl record. And it has a single proposed use: for logging coordinates of nuclear waste.
Obsolescence affects archivability more than anything else. I can't even open up documents from 10 years ago, much less worry about the media it's been stored on. The media can become secondary. While DVDs will probably last 50 years, good luck finding a functional DVD player/reader in a few decades, as it's the weak link in that workflow. Just ask any Betamax user about the difficulty in finding quality machines for transfers.