I recently discovered another aerial steal weapon animation (not default). I can't say for sure that I'm the only one who discovered this move, but I searched the web and found nothing. Who knows, maybe there are other new animations that we haven't seen before?
So how do you do it? While there's no certain way, this might help:
1) Be on one line with the enemy and make sure it's perpendicular with a wall.
2) Run up that wall in the right line, jump from the wall, do the first slash in the air, and land second one on the enemy (it's the weapon pick up button).
3) Of course, the enemy should be weak.
4) Place the camera like I do, while finishing the move. Should increase chances I guess.
P.S. This move is also available in "The Two Thrones".
P.P.S. It's also available in the PSP versions of the WW and T2T (Revelations and Rival Swords).