Interesting.
The concept is very similar to SAS+ on european routes. This is certainly good news for me as a BA Gold. I can now use AB for topping up my TP-level. Also, I can actually fly AB as I don't fly economy if I can avoid it.
Now, will that mean a nice lounge at Tegel? The ARN lounge at Terminal 2 is not that bad but often crowded.
Any news when the new Berlin airport will open?