The paper I saw from ICAO for the en-route segment said 15nm when operating directly behind and that the wake turbulence
could be greater than other heavy classed aircraft at 1000ft below, and greater vertical seperation is
advised !!!
So as usual the situation is as clear as mud!
The final decision won't be made until early next year after further tests and trials, but with the FAA being part of the evaluation panel maybe they will try and damage the A380 politically. Or am I being too cynical?