Also, I think that we need to start mirroring Wiki[mp]edia dumps to other servers around the globe, as the common GNU/Linux ISOs mirrors do. Also, Library of Congress said some time ago that they are going to save a copy of all the tweets sent to Twitter.[6] When are they going to save a copy of Wiki[mp]edia? I hope we have learnt a bit since Library of Alexandria was destroyed.
They've actually just reached out to us to discuss archiving all of the Wikimedia projects :)
Discussions are in their early stages but I'll happily update as I know more.
--tomasz