The latest news from Eben was " I've just come back from dinner with one of the vendors: one of the topics was getting A+ back in stock. I'd expect us to build some in March for April availability." - but they have sold more than a Millon Pi-3 since then, and cannot make Zeros fast enough.
Start testing with your Zero, or a model B, and hope something is announced next week when the next batch of Zeros is released.
