looks like they will be in production in a few more months, when I get hold of one, I'll see if I can get a magi qt running on there too =)
https://bitcointalksearch.org/topic/m.41385192
From what I saw, it will be based on the Pi Zero W and that device only has half gig of RAM.
I was running the CLI wallet on one for a short time and with most unnecessary services disabled in Raspbian it was choking and struggling to keep in sync with the blockchain (CLI wallet uses, on average, 650-750 MB RAM). I guess if the GUI wallet is a bit more optimized, it might work but I'd stay away from this one device personally.
I was always under the impression that running a wallet under a daemon was much lighter than the qt version (following my conversations with the EGC dev team), maybe its not the case for all coins - I'll have to do some experimentation when I get my hands on the staker to see if its possible to run mulitple PoS wallets under the PiZero - at least it'll be a fun task