Certainly

I certainly keep backups of all of Vimm's Lair. After all I'd feel terrible if (for example) a lightning strike fried the server and destroyed 20 years of work. The Vault is several TB large, way too big for disc backups, so I keep a constant copy on a another computer.

Are there any plans to backup the vault, and/or create an alternate mirror of the entire site?

I'm kinda worried that one day Nintendo'll send their DMCA's here and we'll lose a lot of content.