I always wish our players well when they leave, unless given ammo to do otherwise. Diouf for instance.
With Kewell, I sympathise with him because of all the injuries, but I do not think that he gave his all for the club. I think his attitude at times was suspect.
So for me, I won't be looking out for his results or performances, nor will I be clapping and singing his name if he returns to Anfield, but I won't be in the good riddance booing section either.