The AB CEO yesterday told the staff repeatedly that the deal was signed on wednestay night at 21:33. So i guess it is signed, however, with Lufthansa, not Eurowings. And of course pending approval of the boards and relevant authorities. It is a marginal deal in my opinion, 1.2 billion € over six years for 37 to 38 wet leases and 2 or 3 dry leases is not a real good deal at all.
The slot situation will be interesting, as airberlin is apparently only transferring aircraft (and crew) to Lufthansa, but not slots, they will remain with airberlin.