My guess based on all this is that DVDs will basically end up with the same status as Blu-Rays now.
I was pretty sure it was the general opinion that the original injunction was worded in such a way that even the Vault solution would not satisfy the DVD requirements.
The bit you are looking for is point 4 - "does not make a persistent playable copy of any title".
http://www.dvdcca.org/documents/DVDCCA-v-Kaleidescape-Judgment-and-Permanent-Injunction-Order-20120308.pdf
The injunction was a whole can of worms last time it was looked at, and I believe what is happening is that this same injunction will come into effect on the 30th Nov 2014. It raised lots of questions over support and software updates to units which currently have DVD capabilities.
Anyone else notice the legal update page is missing from the Kal site, and the DVD CCA have put up a header on their site for their statement, but no statement to be seen yet?! Shoddy!
...so I guess the best you could do if you really cannot make an archive copy of a DVD using a vault would be to actually play back from the vault itself (so one title from each vault would be accessible at once).