Its already there using Pappenheimer's vec_diff. Lets say the result of the formula is like so.
vector_of_speed.x = -5
vector_of_speed.y = 10
vector_of_speed.z = 15
That means the object has a
X-SPEED = rotating at 5 degrees per frame.(because abs(X) = 5)
X-DIRECTION = rotating anti-clockwise (because X is a negative number)
Y-SPEED = tilting at 10 degrees per frame.(because abs(Y) = 10)
Y-DIRECTION = tilting clockwise(upwards?) (because Y is a positive number)
Z-SPEED = tilting at 15 degrees per frame.(because abs(Z) = 15)
Z-DIRECTION = rolling clockwise (because Z is a positive number)