That that backfires now is not a reason to say it was bad of them to do this in the first place.
Also, there is nobody guilty until they've been proven guilty.
If this is a smear job and it comes out as such in the longer term then wikileaks stature will only grow, if it isn't and Assange steps down I don't doubt that the next person to take his place will know that he/she is living in a glass box and needs to act accordingly.
wikileaks > Julian Assange.